Abdominal aortic aneurysm facts An aneurysm is an abnormal area of localized widening of a blood vessel. The aorta bulges at the site of an aneurysm like a weak spot on a worn tire. Aortic aneurysms are typically ...

Abdominal aortic aneurysm facts An aneurysm is an abnormal area of localized widening of a blood vessel. The aorta bulges at the site of an aneurysm like a weak spot on a worn tire. Aortic aneurysms are typically ...

Hereditary spherocytic hemolytic anemia is a rare blood disorder characterized by defects within red blood cells (intracorpuscular) that result in a shortened survival time for these cells. Red blood cells (erythrocytes) normally circulate for a f...

Primary aldosteronism (al-DOS-tuh-ro-niz-um) is a type of hormonal disorder that leads to high blood pressure. Your adrenal glands produce a number of essential hormones. One of these is aldosterone, which balances sodium and potassium in your blo...

What is sickle cell anemia? Sickle cell anemia (sickle cell disease) is a disorder of the blood caused by an inherited abnormal hemoglobin (the oxygen-carrying protein within the red blood cells). The abnormal hemoglobin causes distorted (...

What is sickle cell anemia? Sickle cell anemia (sickle cell disease) is a disorder of the blood caused by an inherited abnormal hemoglobin (the oxygen-carrying protein within the red blood cells). The abnormal hemoglobin causes distorted (...

What is angina? The heart is the pump responsible for circulating blood throughout the body. Myocardium (myo=muscle + cardium=muscle) is the heart muscle that contracts to pump that blood and like any other muscle, it requires oxygen rich ...

The heart is the pump responsible for circulating blood throughout the body. Myocardium (myo=muscle + cardium=muscle) is the heart muscle that contracts to pump that blood and like any other muscle, it requires oxygen rich blood for energy. Angina...

Introduction to aortic dissection The aorta is the large blood vessel that leads from the heart and carries blood to the rest of the body. It originates at the aortic valve at the outlet of the left ventricle of the heart and ascends withi...

What is aortic stenosis? Aortic stenosis is abnormal narrowing of the aortic valve. A number of conditions cause disease resulting in narrowing of the aortic valve. When the degree of narrowing becomes significant enough to impede the flow...

Aortic stenosis is abnormal narrowing of the aortic valve. A number of conditions cause disease resulting in narrowing of the aortic valve. When the degree of narrowing becomes significant enough to impede the flow of blood from the left ventricle...

A heart arrhythmia (uh-RITH-me-uh) is an irregular heartbeat. Heart rhythm probl...

A heart arrhythmia (uh-RITH-me-uh) is an irregular heartbeat. Heart rhythm problems (heart arrhythmias) occur when the electrical signals that coordinate the heart's beats don't work properly. The faulty signalling causes the heart to beat too fas...

Atrial fibrillation (A-fib) is an irregular and often very rapid heart rhythm (a...

Atrial fibrillation (A-fib) is an irregular and often very rapid heart rhythm (arrhythmia) that can lead to blood clots in the heart. A-fib increases the risk of stroke, heart failure and other he...

Carcinoid syndrome is a disease consisting of a combination of symptoms, physical manifestations, and abnormal laboratory findings. Carcinoid syndrome is seen in individuals who have an underlying carcinoid tumour with spread to the liver. Carcino...

Carcinoid syndrome is a disease consisting of a combination of symptoms, physical manifestations, and abnormal laboratory findings. Carcinoid syndrome is seen in individuals who have an underlying carcinoid tumour with spread to the liver. Carcino...

Childhood acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many immature lymphocytes (a type of white blood cell). Childhood acute lymphoblastic leukemia (also called acute lymphocytic leukemia or A...

Duchenne muscular dystrophy (DMD) is a rare muscle disorder but it is one of the most frequent genetic conditions affecting approximately 1 in 3,500 male births worldwide. It is usually recognized between three and six years of age. DMD is charact...

An epidemic is defined as occurring when "new cases of a certain disease, in a given human population during a given time period, substantially exceed what is expected based upon recent experience." Pediatric obesity has reached epidemic proportio...

What is congestive heart failure (CHF)? Heart failure describes the inability or failure of the heart to adequately meet the needs of organs and tissues for oxygen and nutrients. This decrease in cardiac output, the amount of blood that th...

COVID-19 is a highly contagious respiratory illness caused by the novel coronavirus SARS-CoV-2. It was first identified in Wuhan, China in late 2019 and has since spread globally, leading to a pandemic. Symptoms of COVID-19 can range from mild to ...

General DiscussionThe word "neurasthenia" is a term that has fallen into disuse among psychiatrists in the United States and Australia. It remains in use in the United Kingdom. Where it is used, it covers a wide spectrum of symptoms inclu...

Diabetic ketoacidosis is a serious complication of diabetes that occurs when you...

Diabetic ketoacidosis is a serious complication of diabetes that occurs when you...

General DiscussionEisenmenger syndrome is a rare progressive heart condition that develops in some individuals with structural malformations of the heart that are present from birth (congenital heart defects). The disorder is characterize...

Emphysema is a lung disease that usually develops after a long period of smoking. Chronic bronchitis and emphysema are both types of lung disorders that are classified as chronic obstructive pulmonary disease (COPD) (COPD). COPD is an umbrella ter...

Endocardial fibroelastosis (EFE) is a rare heart disorder that affects infants and children. It is characterized by a thickening within the muscular lining of the heart chambers due to an increase in the amount of supporting connective tissue (ine...

Endocarditis is a serious inflammation of one of the four heart valves....

Endocarditis is a serious inflammation of one of the four heart valves....

Pediatric cardiomyopathy is a rare heart condition that affects infants and children. Specifically, cardiomyopathy means disease of the heart muscle (myocardium). Several different types of cardiomyopathy exist and the specific symptoms vary from ...

Fibrosing Alveolitis, also known as Pulmonary Fibrosis, is a lung condition that affects the tissues that support the air sacs. As a result, it is more difficult for them to absorb the necessary oxygen for respiration. The lung tissues thicken and...

General DiscussionWeil syndrome, a rare infectious disorder, is a severe form of the bacterial infection caused by Leptospira bacteria known as leptospirosis. Weil syndrome is characterized by dysfunction of the kidneys and liver, abnorma...

The word "neurasthenia" is a term that has fallen into disuse among psychiatrists in the United States and Australia. It remains in use in the United Kingdom. Where it is used, it covers a wide spectrum of symptoms including the sensation of pain ...

Giant cell myocarditis is a rare cardiovascular disorder that occurs for unknown reasons (idiopathic). It is characterized by inflammation of the heart muscle (myocardium), a condition referred to as myocarditis. Inflammation is caused by widespre...

Group B Strejsonococcus (GBS) is a type of bacteria that is commonly found in the gastrointestinal tract, vagina, and rectum of healthy individuals. While GBS is usually harmless in healthy adults, it can cause serious infections in newborn babies...

A heart attack occurs when the flow of blood to the heart is severely reduced or...

Cardiac catheterization (also called cardiac cath or coronary angiogram) is an invasive imaging procedure that tests for heart disease by allowing your doctor to see how well your heart is functioning. During the test, a long, narrow tube, called ...

Cardiac catheterization (also called cardiac cath or coronary angiogram) is an invasive imaging procedure that tests for heart disease by allowing your doctor to see how well your heart is functioning. During the test, a long, narrow tube, called ...

What Is Restrictive Cardiomyopathy? Restrictive cardiomyopathy, the rarest form of cardiomyopathy, is a condition in which the walls of the lower chambers of the heart (the ventricles) are abnormally rigid and lack the flexibility to expan...

Restrictive cardiomyopathy, the rarest form of cardiomyopathy, is a condition in which the walls of the lower chambers of the heart (the ventricles) are abnormally rigid and lack the flexibility to expand as the ventricles fill with blood. ...

Heart disease is the leading cause of death among women. An estimated 90% of women have at least one risk factor for heart disease. Heart attack symptoms can be different for women than for men. Younger women wit...

Heart disease is the leading cause of death among women. An estimated 90% of women have at least one risk factor for heart disease. Heart attack symptoms can be different for women than for men. Younger women wit...

According to the American Heart Association, about 5 million Americans are diagnosed with valvular heart disease each year. What Is Valvular Heart Disease? Heart valve disease occurs when your heart's valves do not work the way the...

What Is a Biventricular Pacemaker? Leads are implanted through a vein into the right ventricle and into the coronary sinus vein to pace or regulate the left ventricle. Usually (but not always), a lead is also implanted into the right atriu...

What Is a Biventricular Pacemaker? Leads are implanted through a vein into the right ventricle and into the coronary sinus vein to pace or regulate the left ventricle. Usually (but not always), a lead is also implanted into the right atriu...

Histoplasmosis is an infection caused by the fungus Histoplasma. The fungus can be found in the environment, particularly in soil with a high concentration of bird or bat droppings. Histoplasma is mostly found in the central and eastern United Sta...

High blood sugar (hyperglycemia) affects people who have diabetes. Several facto...

General DiscussionPediatric cardiomyopathy is a rare heart condition that affects infants and children. Specifically, cardiomyopathy means disease of the heart muscle (myocardium). Several different types of cardiomyopathy exist and the s...

General DiscussionGiant cell myocarditis is a rare cardiovascular disorder that occurs for unknown reasons (idiopathic). It is characterized by inflammation of the heart muscle (myocardium), a condition referred to as myocarditis. Inflamm...

Childhood acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many immature lymphocytes (a type of white blood cell). Childhood acute lymphoblastic leukemia (also called acute lymphocytic leukemia or A...

Leukoedema is a benign condition that affects the mucous membranes inside the mouth, causing them to appear white or grayish in color. It is often mistaken for oral thrush or leukoplakia, but it is actually a harmless and temporary condition that ...

Congenital lobar emphysema is a rare respiratory disorder in which air can enter the lungs but cannot escape, causing overinflation (hyperinflation) of the lobes of the lung. It is most often detected in newborns or young infants, but some cases d...

Lung cancer facts Lung cancer is the number one cause of cancer deaths in both men and women in the U.S. and worldwide. Cigarette smoking is the principal risk factor for development of lung cancer. Passive exposure to tobac...

Lung cancer facts Lung cancer is the number one cause of cancer deaths in both men and women in the U.S. and worldwide. Cigarette smoking is the principal risk factor for development of lung cancer. Passive exposure to tobac...

Systemic lupus erythematosus (SLE) is an autoimmune disease. SLE is characterized by the production of unusual antibodies in the blood. SLE is eight times more common in women than men. The cause(s) of SLE is (ar...

Mallory-Weiss syndrome refers to a tear or laceration of the mucous membrane, most commonly at the point where the esophagus and the stomach meet (gastroesophageal junction). Such a tear may result in severe bleeding from the gastrointestinal trac...

Mallory-Weiss syndrome refers to a tear or laceration of the mucous membrane, most commonly at the point where the esophagus and the stomach meet (gastroesophageal junction). Such a tear may result in severe bleeding from the gastrointestinal trac...

Mesothelioma is a rare form of cancer (malignancy) that most frequently arises from the cells lining the sacs of the chest (the pleura) or the abdomen (the peritoneum). Pleural mesothelioma is the most common form, often presenting with symptoms i...

Milk allergy is an abnormal response by the body's immune system to milk and products containing milk. It's one of the most common food allergies in children. Cow's milk is the usual cause of milk allergy, but milk from sheep, goats, buffalo and o...

Marinesco-Sjogren syndrome (MSS) is a rare genetic disorder that affects multiple organ systems of the body. Common symptoms include difficulty coordinating voluntary movements due to degeneration (atrophy) of the cerebellum (cerebellar ataxia), c...

General DiscussionPediatric cardiomyopathy is a rare heart condition that affects infants and children. Specifically, cardiomyopathy means disease of the heart muscle (myocardium). Several different types of cardiomyopathy exist and the s...

Hypertrophic cardiomyopathy (HCM) is a disease in which the heart muscle becomes...

What is pericarditis? The heart muscle has a tight covering that surrounds it, a lining sac called the pericardium (peri=around +cardium=heart). This sac actually has two layers. The visceral pericardium is only one cell layer thick and fi...

Pneumonia is a lung infection that can be caused by bacteria, viruses, or fungi. It causes inflammation in the air sacs in the lungs, leading to symptoms such as cough, fever, difficulty breathing, and chest pain. Pneumonia can range from mild to ...

Preeclampsia is a pregnancy complication characterized by high blood pressure and signs of damage to another organ system, most often the liver and kidneys. Preeclampsia usually begins after 20 weeks of pregnancy in women whose blood pressure had ...

General DiscussionWolff-Parkinson-White (WPW) syndrome is a rare congenital heart disorder involving irregularities in the electrical system of the heart. In individuals with WPW syndrome, an abnormal alternate electrical pathway (accesso...

Pernicious anemia is a rare blood disorder characterized by the inability of the body to properly utilize vitamin B12, which is essential for the development of red blood cells. Most cases result from the lack of the gastric protein known as intri...

Pulmonary alveolar proteinosis is a lung disorder characterized by a build-up of proteins, lipids, and other substances (together known as surfactants) in the lungs' air sacs, or alveoli. The alveoli are the air-holding cells in the lungs. The exc...

Pulmonary angiitis is a term used to describe a collection of disorders with both a vascular (angiitis) and granulomatous components. It means inflammation of blood vessels in the lungs.  There are five unique clinical syndromes that ...

Damage and scarring in lung tissue lead to pulmonary fibrosis. The scars thicken the tissue around and between the air sacs in your lungs, making it difficult for oxygen to pass into the bloodstream.  The reason for scarring ca...

General DiscussionSecondary pulmonary hypertension is a disorder of the blood vessels in the lungs. It usually is the result of other lung diseases or related diseases in other organs. Affected individuals have high blood pressure (hypert...

Lymphomatoid granulomatosis is a rare disorder characterized by overproduction (proliferation) of white blood cells called lymphocytes (lymphoproliferative disorder). The abnormal cells infiltrate and accumulate (form lesions or nodules) within ti...

Pump lung, (also known as Shock Lung), is inflammatory lung damage.  Pump lung is caused by fluid buildup in the lungs' small air sacs (called alveoli), which makes breathing very difficult. It also results in severely low bloo...

Acquired Pure Red Cell Aplasia is a rare bone marrow disorder characterized by an isolated decline of red blood cells (erythrocytes) produced by the bone marrow. Affected individuals may experience fatigue, lethargy, and/or abnormal paleness of th...

Thrombotic thrombocytopenia purpura (TTP) is a rare, serious blood disease. Major symptoms may include a severe decrease in the number of blood platelets (thrombocytopenia), abnormal destruction of red blood cells (hemolytic anemia), and disturban...

Recurrent Respiratory Papillomatosis (RRP) is the respiratory condition characterised by the presence of recurrent wart-like growths called papillomas around the vocal cords in the respiratory tract. It is caused by the Human Papill...

General DiscussionRomano-Ward syndrome is an inherited heart (cardiac) disorder characterized by abnormalities affecting the electrical system of the heart. The severity of Romano-Ward syndrome varies greatly from case to case. Some indiv...

Androgen insensitivity refers to an inability of the body to respond properly to male sex hormones (androgens) produced during pregnancy. This occurs because of a change (mutation) in a gene involved in the production of the protein inside cells t...

Androgen insensitivity refers to an inability of the body to respond properly to male sex hormones (androgens) produced during pregnancy. This occurs because of a change (mutation) in a gene involved in the production of the protein inside cells t...

The sarcoid of boeck (sarcoidosis) is a chronic inflammatory disease that can affect any organ in the body, but most often involves the skin and lungs.  Sarcoid of boeck is characterized by the formation of small, round bumps (...

Secondhand smoke is the combination of smoke from the burning end of a cigarette and the smoke exhaled by the smoker. It is dangerous to both smokers and nonsmokers. Secondhand smoke contains more than 7000 chemicals, including 70 that can cause c...

Bloom syndrome is a rare genetic disorder characterized by short stature; increased sensitivity to light (photosensitivity); multiple small dilated blood vessels on the face (facial telangiectasia), often resembling a butterfly in shape; immune de...

Mucopolysaccharidoses, which are also known as mucopolysaccharide storage (MPS) diseases, are a group of rare genetic disorders caused by the deficiency of one of ten specific lysosomal enzymes. The lysosomes are particles bound in membranes withi...

General DiscussionEndocardial fibroelastosis (EFE) is a rare heart disorder that affects infants and children. It is characterized by a thickening within the muscular lining of the heart chambers due to an increase in the amount of suppor...

Introduction The superior vena cava is a large vein located in the upper chest, which collects blood from the head and arms and delivers it back to the right atrium of the heart. If this vein is compressed by outside structures, or if a th...

Large arteries Open pop-up dialog box Close Large arteries Large arteries Takayasu's arteritis is a form of vasculitis — inflammation of the blood vessels — that damages the large arteries, especially the aorta. Chamber...

Vascular disease includes any condition that affects the circulatory system. As the heart beats, it pumps blood through a system of blood vessels called the circulatory system. The vessels are elastic tubes that carry blood to every part of the bo...

Vascular disease includes any condition that affects the circulatory system. As the heart beats, it pumps blood through a system of blood vessels called the circulatory system. The vessels are elastic tubes that carry blood to every part of the bo...

Torulosis is an airborne disease. It is more famously referred to as cryptococcosis. When you inhale infected dust, torulosis slowly spreads throughout your lungs, presenting as pneumonia. It could potentially be fatal. Sometimes, i...

Esophageal atresia (EA) is a rare birth defect in which the esophagus (the tube that connects the throat with the stomach) does not develop normally. In infants with EA, the esophagus is usually separated into two parts, an upper and lower segment...

Usual Interstitial Pneumonia (UIP) is a radiologic and histopathologic pattern of interstitial lung disease.  The prognosis of usual interstitial pneumonia (UIP) is poor as the current therapies related to it are of unproven va...

What is a ventricular septal defect (VSD)? A ventricular septal defect (VSD) is a heart malformation present at birth. Any condition that is present at birth can also be termed a "congenital" condition. A VSD, therefore, is a type of conge...

What is a ventricular septal defect (VSD)? A ventricular septal defect (VSD) is a heart malformation present at birth. Any condition that is present at birth can also be termed a "congenital" condition. A VSD, therefore, is a type of conge...

General DiscussionVentricular septal defects are heart defects that are present at birth (congenital). The normal heart has four chambers. The two upper chambers, known as atria, are separated from each other by a fibrous partition known ...

General DiscussionWolff-Parkinson-White (WPW) syndrome is a rare congenital heart disorder involving irregularities in the electrical system of the heart. In individuals with WPW syndrome, an abnormal alternate electrical pathway (accesso...

Takayasu arteritis is a rare disorder characterized by the progressive inflammation of one or more of the larger arteries leading from the heart. The main artery of the heart (aorta) and the pulmonary (lung) artery, among others, may be affected. ...