Medical glossary

A

A1C (HbA1c,hemoglobin A1C)

A blood test that shows your average blood sugar over roughly the past 2 to 3 months.

Allergen (allergens)

A substance, such as pollen or a food, that causes an allergic reaction in some people.

Anaphylaxis

A severe, life-threatening allergic reaction that needs emergency treatment right away.

Anemia

When you do not have enough healthy red blood cells or hemoglobin to carry oxygen through the body.

Antibiotic (antibiotics)

A medicine that treats infections caused by bacteria. Antibiotics do not work against viruses such as colds or flu.

Arrhythmia (arrhythmias)

A heartbeat that is too fast, too slow or irregular.

Arthritis

Swelling and tenderness of one or more joints, causing pain and stiffness.

Assisted living

Housing for people who need some help with daily activities but not round-the-clock medical care.

Asthma

A long-term condition in which the airways become swollen and narrow, causing wheezing, coughing and shortness of breath.

Atrial fibrillation (AFib,A-fib)

A common type of irregular heartbeat that raises the risk of stroke.

B

Benign

Not cancer. A benign growth does not spread to other parts of the body.

Biopsy (biopsies)

Removing a small sample of tissue so it can be examined under a microscope.

Blood glucose (blood sugar)

The amount of sugar in your blood at a given moment. Your body uses glucose for energy.

Board certification (board certified,board-certified)

A credential showing a doctor passed exams and met standards set by a specialty board, beyond the basic license to practice.

Body mass index (BMI)

A number calculated from weight and height that is used as a screening tool for weight categories. It does not directly measure body fat.

C

Cholesterol

A waxy substance in your blood. Your body needs some, but high levels of certain types can build up in arteries.

Coinsurance

Your share of the cost of a covered service as a percentage, such as 20%, usually after you meet your deductible.

Colonoscopy

An exam that uses a thin, flexible camera to look inside the colon and rectum, often used for cancer screening.

Complete blood count (CBC)

A common blood test that measures red blood cells, white blood cells and platelets.

Copay (copayment,co-pay,copays)

A fixed amount you pay for a covered service, such as $30 for a doctor visit.

COPD

Chronic obstructive pulmonary disease: long-term lung disease, including emphysema and chronic bronchitis, that makes breathing harder.

Cortisol

A hormone made by the adrenal glands that helps control stress response, blood sugar and metabolism.

CT scan (CAT scan)

Computed tomography: a scan that uses X-rays taken from many angles to create cross-section pictures of the body.

D

Deductible (deductibles)

The amount you pay for covered care each plan year before your insurance starts paying its share.

Dental plaque

A sticky film of bacteria that forms on teeth. Hardened plaque is called tartar.

E

Echocardiogram

An ultrasound of the heart that shows how it pumps and how its valves work.

Electrocardiogram (ECG,EKG)

A quick, painless test that records the electrical activity of your heart.

Enamel (tooth enamel)

The hard outer layer that protects your teeth.

Endoscopy

A procedure that uses a thin tube with a camera to look inside the body, such as the esophagus and stomach.

EPO

Exclusive provider organization: a plan that covers in-network care only, except emergencies, and often does not require referrals.

Explanation of benefits (EOB)

A statement from your insurer showing what a provider billed, what the plan paid and what you may owe. It is not a bill.

F

Flexible spending account (FSA)

An employer account that lets you set aside pre-tax money for eligible health costs, usually within a plan year.

G

Generic drug (generic drugs,generics)

A medicine with the same active ingredient, strength and effect as a brand-name drug, usually at a lower price.

GERD (acid reflux disease)

Gastroesophageal reflux disease: frequent acid reflux that can cause heartburn and irritate the esophagus.

Gingivitis

Early gum disease that causes red, swollen gums that may bleed. It can usually be reversed with good care.

Glycemic index

A ranking of carbohydrate foods by how quickly they raise blood sugar compared with pure glucose.

Good faith estimate

An estimate of expected charges that providers must give uninsured or self-pay patients before scheduled care, under federal rules.

H

HDL cholesterol (HDL)

Often called "good" cholesterol because it helps carry cholesterol away from the arteries.

Health savings account (HSA)

A tax-advantaged account for medical costs that you can open if you have a qualifying high-deductible health plan.

Hemoglobin

The protein in red blood cells that carries oxygen.

HMO

Health maintenance organization: a plan that usually requires you to use in-network providers and get referrals to see specialists.

Hospice

Care for people with a terminal illness that focuses on comfort and quality of life rather than cure.

Hypertension (high blood pressure)

Blood pressure that stays too high over time. It often has no symptoms but raises the risk of heart disease and stroke.

I

In-network (in network)

Doctors, hospitals and pharmacies that have a contract with your insurance plan, which usually means lower costs for you.

Inflammation

The body's response to injury or infection. It can be short-term and helpful, or long-term and linked to disease.

Insulin resistance

When the body's cells do not respond well to insulin, so the body needs more insulin to keep blood sugar in range.

Irritable bowel syndrome (IBS)

A common condition that affects the large intestine and causes cramping, bloating, gas, diarrhea or constipation.

L

LDL cholesterol (LDL)

Often called "bad" cholesterol because high levels can lead to buildup in arteries.

M

Malignant

Cancerous. Malignant cells can grow into nearby tissue and spread to other parts of the body.

Mammogram (mammography)

An X-ray of the breast used to screen for breast cancer.

Medicaid

A public health coverage program run by states and the federal government for people with limited income and certain other groups.

Medicare

Federal health insurance for people 65 and older and for some younger people with disabilities or certain conditions.

Menopause

The time when menstrual periods stop for good, confirmed after 12 months without a period.

Metabolic panel (BMP,CMP)

A group of blood tests that check blood sugar, electrolytes and kidney function, and in the comprehensive version, liver function too.

Migraine (migraines)

A type of headache that can cause intense throbbing pain, often with nausea and sensitivity to light or sound.

MRI

Magnetic resonance imaging: a scan that uses a strong magnet and radio waves to create detailed pictures of the inside of the body.

N

National Provider Identifier (NPI)

A unique 10-digit number assigned to health care providers in the United States.

Neuropathy (peripheral neuropathy)

Damage to nerves outside the brain and spinal cord, often causing numbness, tingling or pain in the hands and feet.

No Surprises Act

A federal law that protects people from most surprise bills for emergency care and certain out-of-network care at in-network facilities.

O

Osteoporosis

A condition in which bones become weak and brittle, making fractures more likely.

Out-of-network (out of network)

Providers without a contract with your plan. Care from them usually costs more, and some plans do not cover it at all.

Out-of-pocket maximum (out-of-pocket limit)

The most you have to pay for covered care in a plan year. After you reach it, the plan pays 100% of covered in-network costs.

Over-the-counter (OTC)

Medicines you can buy without a prescription.

P

Palliative care

Care focused on relief from symptoms and stress of a serious illness. It can be given alongside treatment.

Pap test (Pap smear)

A screening test that collects cells from the cervix to check for changes that could lead to cervical cancer.

Periodontitis (periodontal disease)

Advanced gum disease that damages the tissue and bone holding teeth in place.

Polycystic ovary syndrome (PCOS)

A common hormone condition that can cause irregular periods, excess androgen levels and ovarian cysts.

Postpartum

The period after giving birth.

PPO

Preferred provider organization: a plan that lets you see in-network and out-of-network providers, usually without referrals, at a higher cost.

Prediabetes

Blood sugar that is higher than normal but not high enough to be diagnosed as type 2 diabetes.

Premium (premiums)

The amount you pay for your health insurance every month, whether or not you use care.

Prior authorization (preauthorization,pre-authorization)

Approval your insurance plan requires before it will cover certain services, tests or medicines.

Prognosis

The likely course and outcome of a disease.

R

Referral (referrals)

A written order from your primary care provider to see a specialist or get a service. Some plans require it.

Remission

A period when signs and symptoms of a disease lessen or disappear.

S

Skilled nursing facility (SNF)

A facility that provides short-term nursing and rehabilitation care, often after a hospital stay.

Spirometry

A breathing test that measures how much air you can breathe out and how fast.

Stroke (strokes)

When blood flow to part of the brain is blocked or a blood vessel bursts. It is an emergency: call 911.

T

Telehealth (telemedicine)

Health care delivered by video, phone or online messaging instead of an in-person visit.

Triage

The process of deciding how urgently someone needs care based on how serious their condition is.

Triglycerides

A type of fat in the blood. High levels are linked to a higher risk of heart disease.

TSH

Thyroid-stimulating hormone. A blood test for TSH is usually the first test used to check how the thyroid is working.

Type 2 diabetes

A long-term condition in which the body does not use insulin well and blood sugar stays too high.

U

Ultrasound

An imaging test that uses sound waves to create pictures of organs and tissues. It does not use radiation.

Urgent care

Walk-in care for illnesses or injuries that need attention soon but are not emergencies.

V

Vaccine (vaccines,vaccination)

A product that trains the immune system to recognize and fight a specific germ.