Health Topics A-Z

Gallstones

Stones forming in the gallbladder, most of which never cause symptoms.

Gestational Diabetes

High blood sugar that develops during pregnancy in someone who did not have diabetes before.

Getting a Referral and Prior Authorization

The steps that may be needed before you see a specialist or have a test or treatment covered: a referral from your primary care doctor, approval from your insurer, and the Explanation of Benefits that follows.

Getting Help From a Pharmacy

Community pharmacists, who can advise on medicines and minor illnesses and provide a range of services without an appointment.

Glaucoma

Damage to the optic nerve, often associated with raised pressure inside the eye.

Gout

Sudden severe joint inflammation caused by uric acid crystals, classically in the big toe.

Growth and Development

Tracking a child's growth and developmental milestones over time.

Gum Disease

Inflammation of the gums, from reversible gingivitis to bone-destroying periodontitis.

Gut Health and Immunity

The relationship between the gut microbiome, the intestinal lining and immune regulation.

Hand Hygiene

Removing germs from hands mechanically with soap and water, or chemically with alcohol-based sanitizer.

Having a Blood Test

A sample taken from a vein, usually in the arm, for one of hundreds of different lab tests.

Having an MRI Scan

A scan that uses a strong magnetic field and radio waves to image soft tissue, with no X-rays involved.

Hay Fever

Seasonal allergic rhinitis caused by pollen, with nose, eye and sometimes chest symptoms.

Hay Fever and Pollen

Seasonal allergic rhinitis caused by tree, grass or weed pollen.

HbA1c

A blood test, often called the A1C, reflecting average blood glucose over the preceding two to three months.

Head Injury

Injury to the head, from a minor bump to significant trauma.

Health Literacy

The ability to find, understand and act on health information.

Healthy Teen Relationships

Dating and friendships built on respect, trust, honesty and the freedom to say no, and how to recognize when a relationship is unhealthy.

Hearing Aids

Devices that amplify and shape sound to compensate for hearing loss.

Hearing and the Brain

The relationship between untreated hearing loss and thinking, mood and social life.

Hearing Loss

Reduced hearing, most commonly age-related or noise-induced.

Heart Attack Symptoms

The warning signs of a myocardial infarction, including the ones that are not textbook.

Heart Failure

A condition in which the heart cannot pump efficiently enough to meet the body's demands.

Heat and Medications

How some medicines raise your risk of heat illness, and how heat can damage medicines themselves.

Heat Exhaustion and Heat Stroke

Two heat-related illnesses: heat exhaustion, which is a warning sign, and heat stroke, which is a medical emergency.

Heavy Periods

Menstrual bleeding heavy enough to interfere with physical, social or emotional quality of life.

Hemorrhoids

Swollen blood vessels in and around the anus, sometimes called piles.

Hepatitis A

A liver infection caused by the hepatitis A virus, spread when tiny amounts of stool from an infected person get into food, water or onto hands.

Hepatitis B and C

Viral infections of the liver that can persist for decades without symptoms.

High Platelet and White Cell Counts

High counts on a complete blood count, most often a reaction to something else.

HIV

A virus that damages the immune system, now a manageable long-term condition when treated.

Home Workouts

Training with body weight and household objects, without a gym or equipment.

Hormonal Contraception and Health

The wider health effects of hormonal birth control beyond preventing pregnancy.

Hormone Replacement Therapy

Menopausal hormone therapy: replacing estrogen, with a progestin if you have a uterus, to treat menopausal symptoms.

Hormones and Mood

The effect of hormonal change on mood across the menstrual cycle, pregnancy and menopause.

Hospital Financial Assistance

Charity care and discount programs that hospitals offer to reduce or cancel bills for patients with limited income.

House Dust Mite

A microscopic creature living in bedding and soft furnishings, and a common allergen.

Household Chemicals

Cleaning products, laundry products, drain openers and other chemicals commonly stored at home.

How Vaccines Work

Training the immune system to recognize a germ without having to survive the disease first.

HPV Vaccine

A vaccine that protects against the types of human papillomavirus most likely to cause cancer and genital warts.