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Hair follicle

A sac from which a hair grows and into which an oil gland opens.

Health Canada

The Canadian government agency responsible for national public health. Health Canada oversees and regulates phases I through III of all clinical trials conducted in Canada, and it is their duty to make sure sponsors protect their participants’ safety.


In hemodialysis a machine filters wastes, salts and fluid from your blood when your kidneys are no longer healthy enough to do this work well enough on their own.

Hepatitis A

Hepatitis A is a liver disease caused by the hepatitis A virus (HAV). HAV causes the liver to swell and prevents it from working well. HAV is passed from person to person through fecal matter. Most often it is transmitted because of poor hand washing after using the bathroom or changing a diaper, or before preparing and eating food. Unlike hepatitis B and hepatitis C, it does not become chronic (long-term).

Hepatitis B

Hepatitis B is a liver disease caused by the hepatitis B virus (HBV). HBV causes the liver to swell and prevents it from working well. HBV is passed from person to person through bodily fluids such as blood, semen, or vaginal secretions. Most often it is transmitted through sexual contact or from an infected mother to her infant during birth.


A hepatologist is a doctor who specializes in the study of the liver.


In normal cells, the HER2 protein (made with instructions from the HER2 gene) helps to control cell growth. When the HER2 protein is made in larger than normal amounts by cancer cells, the cells may grow more quickly and can spread to other parts of the body.


A virus that affects the skin or the nervous system, often causing blisters.


A condition that occurs when too much hair grows on a woman’s face or body.


A disease caused by a fungus called Histoplasma. This fungus grows in soil and material contaminated with bat or bird droppings. Breathing the fungal spores can cause infection; it is not contagious between people.


HIV (short for human immunodeficiency virus) weakens your immune system by destroying important cells that fight disease and infection. A ‘deficient’ immune system can’t protect you from illness as it normally would. It is sometimes referred to as ‘the AIDS virus’.


A drug used to dilate (enlarge) the pupil of the eye. This drug is used before eye examinations, before and after eye surgery. It can also be used to treat eye conditions, such as uveitis

Hormone receptor tests

These tests measure the amount of certain proteins, called hormone receptors, in cancer tissue. Hormones can attach to these receptors. Having a lot of hormone receptors means that hormones can help the cancer grow.

Hormone replacement therapy

Hormones (estrogen, progesterone, or both) are used to treat women after menopause to replace the hormones no longer produced by the ovaries.