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Irritable bowel syndrome (IBS) usually starts in early adulthood. It affects twice as many women as men. Approximately 10% to 20% of the population has IBS. No one knows what causes IBS. Some studies suggest that the nerves of the colon may be much more sensitive than usual in people with IBS. The normal movement of food and gas through the colon causes pain, intestinal spasms and an irregular pattern of bowel movements.

Ulcerative colitis and Crohn’s disease are the two main types of inflammatory bowel disease, caused by a malfunctioning immune system. In these diseases, the immune system misfires, causing the lining of the digestive tract to become chronically inflamed and irritated. In irritable bowel syndrome (IBS) there is no obvious inflammation within the digestive tract. The underlying cause of IBS is unknown, but symptoms may arise due to uncoordinated intestinal contractions that affect bowel movements and hypersensitive nerves in the gut.

The prognosis and life expectancy for someone with interstitial lung disease is highly variable. Some people have minimal changes seen on a chest CT scan that hardly change over time. Others can experience very rapid progression that is not slowed by treatment leading to a very poor prognosis.

The amount of scar formation from a skin infection like impetigo or following any skin injury varies from person to person. Some people form larger and darker scars, especially after skin problems that take longer to heal. Skin color can also make a difference in the appearance of a scar.

Hypothyroidism refers to an underactive thyroid gland that is producing and secreting less than normal amounts of thyroid hormone. Hyperthyroidism means that there is abnormally high amounts of thyroid in the blood stream. Hyperthyroidism can happen when the thyroid gland either makes or secretes excess thyroid hormone or when people take a higher dose of thyroid pills than they need.

The treatment of hypoglycemia depends on the cause. For people with diabetes on medications to control blood sugar, frequent hypoglycemia requires adjustments in diet, exercise and medication dose and timing. People with “reactive” hypoglycemia are sensitive to rapid falls in blood sugar levels, even when the level is not dangerously low. The standard advice is to avoid all simple sugars and consider eating smaller meals more frequently to help prevent rapid swings in blood levels.

Stage 1 (Class 1) heart failure means there is evidence that the heart is weaker or stiffer than normal, but the person has no symptoms at rest or with normal daily activities. The prognosis today for stage 1 heart failure is very good because there are a host of medications available to help prevent progression to later stages.

Congestive heart failure, now more often just called heart failure, is a syndrome defined by a constellation of symptoms and signs. Typical features include shortness of breath caused by fluid buildup in the lungs, leg swelling, fatigue and decreased exercise tolerance. Heart failure can be caused either by weak heart muscle cells or a thick stiff heart.

There may be the slightest increase in the risk of pancreatic cancer after a single episode of acute pancreatitis. But if it exists at all, that risk is extremely small. However, people with chronic pancreatitis have about 5% lifetime risk of pancreatic cancer according to some studies.

The cause of multiple sclerosis is unknown though it is considered an autoimmune disease, in which the body’s immune system attacks parts of the nervous system.

The disease may be hereditary. There are hundreds of genetic variants linked to the development of multiple sclerosis and in up to 20% of cases there is a family member with the disease. A sibling or a non-identical twin of a person with multiple sclerosis has a 3% to 5% risk of developing the disease (approximately 30 to 50 times higher than expected) while an identical twin has an even higher risk, in the range of 20% to 40% (approximately 200 to 400 times higher than expected).