Acute respiratory distress syndrome. Known as ARDS
A health problem that occurs when the lungs are not able to give the blood enough oxygen. Patients who have ARDS are very ill and need medical treatment. They usually end up in the intensive care unit (ICU) on a machine that helps them breathe (ventilator).
ARDS is caused by liquid that gets into the lungs, which should never have liquid in them. The goal of treating ARDS is to support the patient in the ICU until his or her lungs heal.
Instructions in writing for your family and the care team, if you are a patient. They state your wishes about medical treatment, should you become too ill to do so yourself. An advance directive is a living will or durable power of attorney. The durable power of attorney gives another person the power to make decisions about your treatment.
Laws about advance directives are different in each state, so you should write one for all states in which you spend a lot of time. An advance directive will not expire unless the person who wrote it writes a new version. Every few years, you should review and update your advance directives.
Allied health professional
A caregiver who is not a doctor or direct care registered nurse but has medical skills. An allied health professional has studied medical care, trained in it, and often earned proof of his or her efforts.
Allied health professionals are in charge of different things. Some offer dietary tips. Some make sure medical records are up-to-date. Some lead or perform medical procedures.
Examples of allied health professionals include:
Emergency medical technicians
Physical and occupational therapists
Physician assistants and nurse practitioners
A medicine that reduces or gets rid of pain, fever or swelling. In the intensive care unit (ICU), the care team put it on or into the patient's body to:
Decrease the patient’s stress
Help the patient sleep through the noise and light of the ICU
Make the patient feel less sick, sore, stiff, forgetful or constipated
An analgesic can also reduce side effects and discomfort caused by a medical procedure.
A medicine put on or into the patient's body to cause a temporary loss of feeling. An anesthetic can also make the patient sleepy.
An anesthetic may help the patient feel more comfortable during an invasive procedure. During this kind of procedure, the skin is broken or a tube is inserted into one of the body's natural openings. This helps the care team see and treat parts inside of the patient's body, such as organs.
A condition in which the level of hemoglobin (blood) is low due to decreased production, increased destruction, or loss of red blood cells.
Medications used to treat and prevent bacterial infections.
Called a-line or art line
A small tube in the artery, usually placed in the wrist. The care team use this tube to check the patient’s blood pressure and take blood samples.
Some patients in the intensive care unit (ICU) need drugs that can harm their bodies over time. If so, they need their blood checked regularly. Having an a-line is more comfortable for them than getting stuck with a needle each time.
A type of blood vessel that carries oxygen-rich blood away from the heart to the rest of the body. This helps a person stay alive.
A medical doctor who oversees all of the patient’s care. The attending physician is also in charge of medical interns, students, and residents (those training to become doctors). He or she can change any decision made by a doctor-in-training.
A force that pushes against the walls of an artery as blood moves through the artery. Having high blood pressure for a long time is dangerous. It stiffens arteries and makes them vulnerable to fat buildup, which can lead to a heart attack, a stroke or kidney failure.
Blood pressure cuff
A wide strip of fabric placed around the arm or leg. The care team automatically or manually inflate it. This helps them assess the amount of blood pressure in the patient’s veins.
One of two kinds of death known by law—the first and most common kind occurs when the heart stops. Brain death occurs when the brain stops working. The heart of the patient who is brain dead may continue to beat, but the patient cannot breathe without machines. He or she cannot have any thoughts or feelings, including pain. When this happens, all life support is turned off. Turned-off support is not the same as withdrawn support. Support is withdrawn when the patient is alive but has chosen to die comfortably over time.
The sudden loss of all heart function. Cardiac arrest is not the same as a heart attack, which occurs when blockage causes sudden damage to the heart. A heart attack may lead to cardiac arrest, but cardiac arrest is usually caused by:
Coronary heart disease
Cardiac arrest permanently damages the brain within four to six minutes of occurring. Ninety-five percent of people who experience it do not survive. Those who do survive are likely to need critical care.
Called heart monitor
A machine that records electrical activity of the heart. It has a screen with lines that move across it, known as tracings. Tracings appear once the care team place leads on the patient’s body. They use tracings to assess and respond to the patient’s heartbeat. Unusual beating can be a chemical or mechanical problem with the heart.
Known as CPR
Medical treatment that supplies oxygen to the lungs and keeps blood flowing in the body of someone whose heart has suddenly stopped. CPR helps the caregiver prevent brain damage until he or she can better treat the patient. The caregiver who does CPR has trained in it. CPR has three steps, called circulation, airway, and breathing, or CAB.
Circulation (done by compressions): The caregiver places both hands on the patient's chest and presses down about two inches. The caregiver does this one hundred times a minute.
Airway: The caregiver positions the patient for breathing.
Breathing: The caregiver opens the patient's mouth and slowly breathes into it two times to make the chest rise. Then the caregiver checks if the patient has a pulse. If not, the caregiver repeats all three steps until the patient has a pulse.
During CPR, the caregiver may also use a machine to restart the heart. CPR does not always work and is not the right treatment for all patients.
A caregiver who makes sure the doctor's plan of care and post-hospital care meets the patient’s needs. These needs are based on culture, health coverage, and other factors in the patient’s life.
A thin, flexible tube inserted into the patient's body so fluids can move into and out of his or her systems. There are many types of catheters, each with a different purpose. A catheter is important in critical care because it provides the patient with:
Food, through the nose or stomach, when the patient is not able to eat
Relief, through the bladder, when the patient is not able to go to the bathroom
Medicine, into the vein, when the patient is feeling pain
Not being able to eat, go to the bathroom, or feel well is the result of illness or medical treatment. The care team often use peripherally inserted central catheters, or PICCs, to help the patient get better. A PICC goes through the arm into a vein until it reaches the heart.
Central venous catheter
Called CVC or central line
A tube in the neck, chest or groin that helps the care team check and treat blood flow. It also helps them give the patient fluids, medicine or nutrients.
Sometimes, the care team put a CVC into a large vein in the arm, which is known as a peripherally inserted central catheter, or PICC. Before placing a CVC, the care team usually give the patient medicine for pain or anxiety. A CVC can stay in the patient’s body for days or weeks, as long as it shows no signs of infection.
A clergy member in the hospital who talks with patients, families and staff. The chaplain provides spiritual support and may help find a clergy member of the patient’s faith to better meet the patient’s spiritual needs. Often the chaplain plays an important role in end-of-life care.
A large tube inserted through the skin into the lungs. The chest tube removes air or blood that makes breathing hard to do for the patient.
Child life specialist
An expert in child development who works with ill children. The child life specialist provides play and distraction therapy. He or she often works with other experts in the pediatric intensive care unit (PICU) to improve the health and well-being of very ill children.
An illness that affects the patient for a long time, sometimes for his or her entire life. Examples of this kind of illness include diabetes and emphysema. The patient may need to visit the doctor often to control symptoms of the illness. Many chronic illnesses do not have cures, so the doctor is likely to focus on improving the patient's quality of life.
Chronic obstructive pulmonary disease
Known as COPD
An illness that makes breathing hard to do. The lungs are too stiff or too floppy. Patients with COPD cough often, producing too much mucus. They may wheeze or feel tightness in their chest. Common COPDs include bronchitis and emphysema. Asthma is also a COPD. It has no cure, but the care team can treat it with medicine.
Medical care for patients whose illness requires close, constant watch by a team of specially trained caregivers. Nearly 80% of Americans will experience this kind of illness, either as the patient or family. Most critical care takes place in an intensive care unit (ICU) or trauma center. Both places of care contain all kinds of machines, tubes, and equipment used to treat the illness.
Critical care nurse
A highly skilled nurse who provides all aspects of care for a very ill patient. This nurse helps all of the people involved in that care talk to one another. He or she has close contact with the patient and family and can often uphold the patient's wishes. The critical care nurse becomes an important part of decision-making with the patient, the family, and the care team.
A registered nurse (RN) who is certified in critical care is known as a CCRN. CCRNs are certified by the American Association of Critical-Care Nurses.
Critical care team
A group of specially trained caregivers who work in a special area of the hospital known as the intensive care unit (ICU). They come from many professions and can help very ill patients get better. The care team often teach the patient and family strategies that improve health and well-being.
Members of the team usually include one or more of these caregivers:
Critical care nurse
Members of the team may also include one or more of these caregivers:
Physician assistant or nurse practitioner
Child life specialist
A machine that sends an electrical charge through the chest to the heart. The care team use the defibrillator to make the patient's heart beat again or to stop it from beating in a bad pattern, which may lead to no heart beat. When the patient's heart stops beating, he or she goes into cardiac arrest. Defibrillation is the act of electrically shocking the heart.
Removing waste from the blood with special medical equipment. Dialysis helps the patient whose kidneys have failed.
A tube in the groin or neck that connects to a machine. The tube and machine work together to clean the patient's blood when his or her kidneys are not able to do so themselves.
Donation after cardiac death
A process that occurs when the patient will not regain health and is removed from life support. If the patient's heart stops beating in a somewhat short timeframe, he or she can be a candidate for organ donation.
Called DNAR or DNR
Instructions on the medical chart written by the doctor but based on patient request. The order tells the care team not to attempt cardiopulmonary resuscitation (CPR) if the patient’s heart stops. It is simply a choice to say no to CPR but yes to all other appropriate medical treatments.
A caregiver who helps plan therapy that destroys cancer cells. The dosimetrist determines how best and safely to supply the amount of radiation the patient needs.
A bag of fluids, medicine, or nutrients that go into the vein to help the patient get better. The bag runs constantly on a pump.
Durable power of attorney
A legal document that gives another person the power to make decisions about the patient's medical treatment. The person only has power if the patient becomes too ill to make decisions on his or her own. What the document includes varies from state to state. It may include:
A sworn, signed statement from the patient that confirms who will make the decisions
A list of medical treatments the patient desires, such as removal of life support
The name and contact information of the decision-maker and two other people, should the original person not be able to make the decisions
The amount of time the person will have this duty
A place of medical care where doctors and nurses stabilize the patient first. Then they transport the patient to the intensive care unit (ICU) or another area of the hospital for further treatment. The ED is not the same as the ICU. In the ED, caregivers determine what kind of care the patient needs and then transfer the patient to a place with that care. Sometimes, they discharge the patient home.
Emergency medical technician
A caregiver who responds to a medical emergency where it has happened. EMTs provide on-the-spot care for an ill patient. Then they bring the patient to the hospital for further medical treatment. Examples of care that EMTs provide include:
Assisting with childbirth
The medical care that a very ill patient receives when he or she will not regain health. Many intensive care units (ICUs) have rules in place for this care. The goal of end-of-life care is to make sure the patient dies as dignified and pain-free as possible. End-of-life care can take place in the hospital, a home or the hospice unit.
A tube connected to a machine that helps the patient breathe. The tube is inserted through the mouth or nose. Oxygen moves from the machine, through the tube, into the lungs, and throughout the body.
Called urinary catheter
A tube inserted into the bladder and kept in place by a balloon that drains the bladder. The urinary catheter helps the care team measure how much urine the patient is producing. It helps them determine if that amount is normal or if the patient’s kidneys are not working in the way they should.
Not being able to perform a function that involves the body, thoughts, feelings or mind. Examples of these functions include:
Caring for oneself
Being aware of one's surroundings
Permission you give to the doctor to treat you, if you are the patient. Before you give permission, the doctor should explain the risks and benefits of the treatment to you. By law, doctors must have informed consent before starting any treatment. If you are too ill to consent, consent will likely be from someone you have chosen ahead of time as your decision-maker.
Medical treatment in a hospital. To receive inpatient care, the patient stays in the hospital for at least one day, but often more. Critical care is almost always inpatient care.
Intensive care unit
An area in the hospital with special equipment and staff, who are known as the critical care team. The care team check on and treat very ill patients all day and all night. Patients come to the ICU from the emergency department or another area of the hospital—usually after surgery. They may also come from a place of care outside of the hospital.
There are many kinds of ICUs, including:
Burn or trauma unit
Coronary care unit, or CCU
Medical intensive care unit, or MICU
Neonatal intensive care unit, or NICU
Neurosurgery intensive care unit, or NSICU
Pediatric intensive care unit, or PICU
Surgical intensive care unit, or SICU
A medical doctor who has studied, trained, and tested in caring for very ill patients. The intensivist is often an expert in one of these areas:
Intra-aortic balloon pump
A machine that helps a weak heart pump blood throughout the body. The machine has a tube that goes into the body's main artery, and the tube has a balloon that inflates and deflates to match the natural beating of the heart.
Intracranial pressure catheter
A small tube placed into the brain. It helps the care team keep an eye on swelling in the brain and, if necessary, drain excess fluid from around the brain.
In a vein.
Called intravenous catheter or IV.
Giving the patient nutrients in the form of liquid through a tube when the patient is not able to eat or his or her digestive system needs to rest. The tube goes into a vein in the arm or neck. Keywords: intravenous, feeding, catheter, IV
Giving the patient fluids, medicine, or nutrients through a tube in a vein. Some patients need this therapy once, and other patients need it nonstop. Intravenous therapy can help the patient:
Regain lost body fluids or moisture
Receive medicine that controls blood pressure or heart rate
Feel numb during an unpleasant medical treatment
it, such as breathing. The patient has no control.
Understanding the terminology used in the intensive care unit ("ICU") is important for patients, caregivers and family members.
This glossary covers most of the words that you may here medical professionals use in the ICU.
Click on any letter to find the glossary term that you are looking for
Glossary of Hospital ICU Terms.
A caregiver who obtains and tests samples from the body. Common samples include blood, urine, tissue and sputum (a mixture of saliva and mucus).
Small pads on the patient’s chest that are clipped onto wires connected to a heart monitor. Leads help the care team check the patient’s heart rate and rhythm.
Medical equipment or treatment that supports or replaces a function of the body, such as breathing. Some patients are on life support for a short amount of time, until their body works on its own again. Other patients are on it for years, if they are in a coma.
Medical treatment that assists the patient with breathing. Mechanical ventilation breathes for the patient or supports his or her breathing efforts. The care team use it on patients whose lungs do not work in the way they should.
A machine that measures a function of the body, such as breathing or heart rate. The machine includes sensors, which are placed on the patient’s body, and two screens. The sensors cause measurements to show up on one screen near the patient’s bed and on another screen elsewhere in the hospital.
The care team use the monitor to watch over the patient's health, even after leaving the room. The monitor often beeps to alert them of changes in the patient’s health. Not all beeps mean there is a problem, and you can ask the nurse if you have questions.
Multiple organ failure
A health problem that occurs when many organs in the body fail. Patients who experience multiple organ failure rely on medical support to breathe, keep good blood pressure, clean their body’s waste, and more. Any illness that brings the patient to the intensive care unit (ICU) can affect other organs in the body. Slowly, one organ after another may start to fail—the first and most common ones being the lungs and kidneys. The second most common organs to fail are the brain and immune system.
Describes members of the critical care team. They have different backgrounds and training in how to care for a very ill patient.
Called heart attack
A health problem that occurs when the heart suddenly stops receiving oxygen-rich blood from the arteries. This happens because fat buildup is blocking the arteries or a clot of blood has moved into the heart. Patients who are having a heart attack usually feel bad pain in their left side, chest, arm or all of those areas. Women may also feel fatigued and nauseous. If not treated right away, a heart attack can damage and even destroy the heart.
A tube placed into the nose, down the throat, and into the stomach to:
Remove acid, fluids, or blood that is leaking from the stomach
Drain drug overdoses and poisonings
The care team often prepare the patient for this tube with a numbing medicine.
The art and science of care for the whole patient. This includes physical, spiritual, emotional and social care. Nursing promotes wellness, restores health, and improves the overall ways in which the patient functions.
Being fed or receiving nutrients that improve healing.
A caregiver who helps the patient relearn life skills. Examples of these skills include grooming, feeding, dressing and balancing a checkbook. The occupational therapist helps the patient live as independently as possible.
A machine with an electrical current that stimulates the heart so it beats at a normal pace. The pacemaker can be placed under the skin for a short amount of time or for the rest of the patient's life.
Medical care for the patient who is very ill and has pain that impairs his or her daily life. Medical treatment does not always stop the pain but can ease it. The easing of pain is palliative care. Palliative care can also prepare the patient and family in coping with an illness. End-of-life care is a form of palliative care, but they are not the same thing. The patient can receive palliative care at any time during his or her illness. End-of-life care, on the other hand, is comfort for the dying patient.
A drug the care team rarely use to prevent the body from moving. The team always give other medicines with the paralytic to relax the patient when he or she is not able to move. The effect of this drug can be reversed.
A person with an illness or injury who needs medical treatment.
Persistent vegetative state
A health problem that occurs after the patient "wakes" from a coma (a state during which the patient is deeply lacking consciousness). After waking, the patient regains low levels of consciousness but is not aware of his or her surroundings. The patient can open his or her eyes, make a face, or make a noise, but these are all automatic functions of the body. The patient cannot "think" or speak. He or she cannot reason with or relate to the surroundings.
To treat the patient who is in this state, the care team prevent infection and provide nutrients. They may also provide therapy that keeps bones, joints, and muscles working.
An expert in drugs who works with the care team to prescribe drugs the patient needs. The pharmacist checks the progress of these drugs during the patient's stay in the hospital.
A caregiver who helps restore a function of the body that involves the muscles, bones, tissues or nerves. With this help, the patient can better move around in daily life (for example, walking, going up and down the stairs). The physical therapist uses techniques such as stretching and heat. These techniques can reduce pain and swelling. They can also prevent permanent physical disability.
A caregiver who can legally determine the cause of illness and treat the illness. In critical care, the doctor is known as an intensivist.
Physician assistant or nurse practitioner
A caregiver trained and licensed in clinical services. He or she works in the intensive care unit (ICU) under the doctor’s lead. Examples of what the physician assistant and nurse practitioner can do include:
Take the patient's medical history
Order and interpret medical tests
Perform medical procedures
They are often the “first responders” to changes in the patient’s health.
Post-intensive care syndrome
PICS is made up of health problems that remain after critical illness. They are present when the patient is in the intensive care unit (ICU) and may persist when the patient returns home. These problems can involve the patient's body, thoughts, feelings, or mind and may affect the family.
A small machine attached to the patient's finger, nose or ear. It detects the pulse and the oxygen levels in the blood.
A medical doctor who prescribes the amount of radiation needed to treat cancer. The amount is different for each patient who has cancer. When choosing the dose, the doctor considers the patient’s overall health and the size and stage of the patient's cancer.
A caregiver who supplies therapy that destroys cancer cells. The radiation therapist positions the patient on a table. Then he or she lines up the parts of the patient's body marked for treatment with rays from a machine. The therapist is not in the room when the rays are applied, but can see and hear the patient from a control area. He or she steps in, if necessary. The patient who receives this therapy should:
Stay very still during treatment
Complete all scheduled treatments
Get regular medical tests so the doctor can assess overall patient health throughout the process
Medical treatment that can make cancer tumors smaller or get rid of them. Radiation therapy can also take away some of the symptoms caused by a tumor or prevent the tumor from spreading.
This kind of therapy sometimes harms normal cells, but they often get better. It usually lasts a few minutes a day, five days a week, for a few weeks. The length of treatment depends on the size and stage of the cancer. The most common side effects of this therapy include:
Changes in the skin
Loss of appetite
The doctor can work with the patient to treat these side effects.
A caregiver who uses an x-ray machine to create an image of the body. Common images include those of tissues, organs or bones. These images help the doctor determine the patient's illness so the doctor can decide how best to treat the illness.
A caregiver trained and licensed in nutrition and illness. The registered dietitian works with the care team and the family to improve the health of the patient who lacks nutrients. The registered dietitian can lead or perform feedings by mouth, tube or vein.
A caregiver with a degree in nursing. The RN has been licensed by a State Board of Nursing. Some RNs in the intensive care unit (ICU) have an additional certification in critical care, called CCRN.
A post-hospital program that helps the patient recover from illness, injury or a medical treatment. The patient often regains strength or relearns a skill that he or she lost.
In critical care, rehab is important because the patient is sometimes bedridden for a long time. He or she may need to gain lost weight or strengthen his or her muscles. Rehab can be continued in the hospital or at home.
Called kidney failure
A health problem that occurs when the kidneys stop working in the way they should. Kidneys remove extra water and poisons from the body. If they fail and are not medically treated, water buildup can cause skin swelling in the arms, legs and face. It can also cause problems with breathing or in other organs. Poisons can affect the brain, and the patient may get sleepy or go into a coma.
A health problem that occurs when the lungs do not work in the way they should.
Respiratory failure can occur during a stay in the intensive care unit (ICU) or be the reason someone is in the ICU. It is caused by health problems that affect breathing, such as:
Chronic obstructive pulmonary disease, or COPD
Acute respiratory distress syndrome, or ARDS
To treat respiratory failure, the care team can strengthen or support the patient's breathing. They can bring up mucus from the patient's lungs or put the patient on a breathing machine.
A caregiver who has special knowledge and practice in healing problems with breathing. The respiratory therapist uses lung treatments to help the patient breathe.
A drug that calms down the patient when he or she is injured or during a medical procedure. The patient who is on a sedative may appear less alert or asleep.
A serious infection in the body that causes the heart, blood vessels, and cells to work in ways other than they should. The patient's response to an infection can cause the body to inflame and the infection to get out of control. Many organs are affected, so the patient becomes very ill.
State of the body when the organs do not get enough oxygen and then blood pressure drops. Some causes of shock include:
Lack of fluids
Severe blood loss
Any massive trauma to the body, such as a car crash
If the care team is not able to reverse shock quickly, the patient's organs start to shut down. Symptoms of shock include:
Cool and clammy skin
A health problem that occurs when the brain stops getting oxygen-rich blood from the artery. An ischemic stroke is caused by a blood clot, and a hemorrhagic stroke is caused by bleeding into the brain. Ischemic strokes are more common than hemorrhagic strokes.
Strokes that occur on one side of the body affect how the other side of the body works. Strokes that occur in the right part of the brain often cause vision problems and memory loss. Strokes that occur in the left part of the brain often cause speech or language problems and memory loss.
Going into the body to fix it. Surgery can fix deformities, defects and injuries. The care team use it to look for illness, remove harmful tissue, and replace organs that do not work well.
Someone who makes medical decisions on the patient's behalf. The surrogate is usually a family member or close friend. The surrogate must be trustworthy, responsible and ready. He or she must know the patient's personal values and consider the pros and cons of each treatment.
If the patient has not chosen a surrogate before becoming ill, the attending physician (doctor) helps the family pick one. The choice is based on hospital or local laws.
Called pulmonary artery catheter
A large tube in the neck or upper chest that goes into the heart. The care team use this tube to measure fluid levels in the heart. This helps them assess how well the heart is working. Having a pulmonary artery catheter after open heart surgery is common.
Medical treatment that takes place over a period of time. Therapy restores or cures a function of the body (for example, destroys cancer cells, heals wounds).
A temporary or permanent tube in the neck, usually for patients who are on a breathing machine for a long time. Other breathing tubes cause injury over time. A tracheostomy can also help the patient get off of the breathing machine.
A hospital for treating injury caused by crashes and violence. Other hospitals may be less prepared to treat such severe injuries.
A process that helps the care team decide whom to treat and when so the sickest patients are seen first.
Giving food in the form of liquid through a tube. The tube goes from the nose to the stomach. It can also go through the skin directly into the stomach or intestines. Patients need tube feedings when they are not able to eat or lack nutrients. A tube feeding is safer and less expensive than an intravenous feeding, but it requires the patient to have a working
stomach and intestines.
A sore that wears away tissue. An ulcer can occur on the skin but most often occurs inside of the body in the gastrointestinal tract, which is known as the GI tract. The GI tract is a set of organs, including the stomach, that digests food and separates nutrients from waste. An ulcer in the GI tract can create a hole in the stomach lining and cause blood vessels to burst.
A powerful drug that causes blood vessels to get smaller. It raises the patient's blood pressure.
Called respirator or breathing machine
A machine that assists the patient with breathing when he or she is having trouble breathing. The machine pumps air into and out of the lungs, like the way a healthy person inhales and exhales. The patient is connected to it by a tube through his or her mouth or nose and is usually sedated. Sedation calms the patient so he or she does not fight against the machine.
The care team will take the patient off of this device slowly, as his or her lungs get better. Patients who need a ventilator for a long time often get a tube placed in their neck.
During this medical procedure, a tube is placed through the skull into the brain. Ventriculostomy helps the care team assess the amount of pressure around the brain. It also helps them remove extra fluid or blood from there, if necessary.
When the brain sends a message to the body to do something, such as lifting an arm. The patient has control.
The care team "wean" or slowly lower the amount of help the patient has with breathing or from medicine. Weaning keeps the patient safe, in case he or she has become dependent on that help.
Medical treatment for healing cur or broken body tissue, such as skin. During wound therapy, the care team clean and apply medicine or nutrients to the wound. Wounds in a healthy person naturally heal over time in these three stages:
The wound swells to get rid of any debris.
The wound grows, and new cells replace damaged ones.
The wound forms a scar (stronger tissue) to prevent future damage.
Some wounds do not heal naturally over time, such as ulcers. Would therapy heals many types of ulcers, especially the ones on the patient's skin.