Diseases and Conditions

Find doctor-approved information about symptoms, causes, diagnosis, treatment and prevention of common diseases and conditions.

Filter By Alphabet
All conditions that start with the letter A
  • Illustration of a human body with close-ups of a normal aorta and one with an abdominal aortic aneurysm

    Abdominal Aortic Aneurysm (AAA)

    Sometimes an area of a blood vessel wall will get weak. It can start to swell like a balloon and…

  • A woman talking to her doctor about bleeding. Abnormal uterine bleeding is heavy or unusual bleeding from the uterus (through the vagina). Vaginal bleeding between periods is a symptom.

    Abnormal Uterine Bleeding

    Abnormal uterine bleeding is any heavy or unusual bleeding from the uterus. In most women, abnormal uterine bleeding is caused…

  • ACL Injury

    An ACL injury is the overstretching or tearing of the anterior cruciate ligament in your knee. It is a common…

  • Acne is a common skin condition. It causes pimples to appear on the face and/or on the back, chest, arms, and neck.

    Acne

    Acne is a common skin condition. It causes bumps on the skin known as pimples to appear on the face…

  • A sick woman with acute bronchitis coughs at her desk. Acute bronchitis is a contagious viral infection that causes inflammation of the bronchial tubes (the airways that carry air into your lungs).

    Acute Bronchitis

    Acute bronchitis is a contagious viral infection that causes inflammation of the bronchial tubes (the airways that carry air into…

  • Stethoscope resting on black chalkboard with the words Addison’s Disease

    Addison’s Disease

    Addison’s disease is a condition that affects your body’s adrenal glands. It interferes with your body’s ability to produce certain…

  • A girl sits at the kitchen table covering her eyes in a stressful way with her homework sitting in front of her.

    ADHD in Children: Symptoms, Diagnosis, and Support

    ADHD is one of the most common developmental disorders of childhood, associated with inattention, hyperactivity, and/or impulsivity.

  • Man sitting on sofa, holding shoulder in pain

    Adhesive Capsulitis (Frozen Shoulder)

    Adhesive capsulitis, or frozen shoulder, is the condition that occurs when inflammation in your shoulder eventually leads to difficulty moving…

  • A distracted student listens to music in a classroom. Attention-deficit hyperactivity disorder (ADHD) is a group of behaviors that makes it difficult to pay attention at school, work, or home.

    Adult ADHD

    Attention-deficit hyperactivity disorder (ADHD) is a group of behaviors that makes it difficult to pay attention at school, work, or…

  • AIDS

    AIDS (acquired immune deficiency syndrome) is a life-threatening condition caused by human immunodeficiency virus (HIV).

  • silhouette of a person drinking, sitting behind bottles of alcohol

    Alcohol Abuse

    Alcohol abuse is a pattern of drinking too much alcohol too often. This can harm your work, school, and…

  • woman putting drops in her eye

    Allergic Conjunctivitis

    Allergic conjunctivitis occurs when the clear, thin membrane that covers your eyeball becomes swollen and irritated. It can cause itching…

  • man with allergies outside blowing his nose, allergic to trees in background

    Allergic Rhinitis (Allergies)

    Allergic rhinitis is the medical term for nasal allergies. These can seasonal or perennial and can be treated medications or…

  • Person pushes hair back to reveal a bald spot. Alopecia areata is a form of hair loss. It’s a non-life-threatening disease of your immune system that affects the hair on your scalp.

    Alopecia Areata (AA)

    Alopecia areata is an autoimmune disease that causes you to lose small, round patches of hair on your head.

  • Patient and doctor sitting down for counseling session

    Alzheimer's Disease

    Alzheimer’s disease is a type of dementia that is most common in people over the age of 65. There is…

  • young boy with adhesive eye patch over his eye

    Amblyopia is sometimes called “lazy eye.” If left untreated, it can affect a child’s vision permanently.

    Amblyopia (lazy eye) develops in childhood when one eye doesn’t work properly with the brain. Left untreated, it can lead…

  • Woman holding clean menstrual pad

    Amenorrhea

    Amenorrhea is a medical term for when a woman does not have menstrual periods.

  • Doctor talking to patient in office

    Anal Fissure

    An anal fissure is a small crack or tear in the thin, moist lining of the lower rectum. It’s a…

  • Doctor talking to patient

    Anal Fistulas

    An anal fistula is an abnormal connection that forms between the anus and the skin outside of it. It usually…

  • Woman injecting emergency medicine (EpiPen) into her leg

    Anaphylaxis

    Anaphylaxis is a life-threatening allergic reaction that needs immediate medical attention.