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 N
  • Nail Fungal Infections

    A nail infection is caused by a fungus. This infection can happen in toenails and fingernails. It is more common…

  • Nasopharyngeal Cancer

    Nasopharyngeal cancer is a malignant tumor that develops in the nasopharynx, the area where the back part of your nose…

  • Mother holding premature baby’s feet with neonatal infant pulse oximeter

    Necrotizing Enterocolitis

    Necrotizing Enterocolitis is an intestinal disease that occurs mostly in premature and sick newborn babies.

  • Newborn baby girl crying and laying on bed in hospital

    Neonatal Abstinence Syndrome

    Neonatal abstinence syndrome (NAS) occurs when a baby is exposed to drugs in the womb. After birth, the baby goes…

  • 3D illustration of a fetus who has spina bifida, a neural tube defect

    Neural Tube Defects

    Neural tube defects are birth defects affecting a baby’s spine, spinal cord, or brain.

  • Hands of woman who has neurofibromatosis, a genetic disorder that causes tumors on skin.


    Neurofibromatosis (NF) is a genetic disorder. It affects your nervous system and nerve cells. The condition produces tumors on your…

  • Nightmares and Night Terrors

    Learn about nightmares and night terrors in children.

  • Noise-Induced Hearing Loss

    Noise-induced hearing loss is permanent hearing loss that is caused by being around loud noises over a long period of…

  • two hands wearing rubber gloves and feeling a woman's lymph-nodes in her neck to test for non-hodgkin lymphoma

    Non-Hodgkin Lymphoma

    Non-Hodgkin lymphoma is cancer of the lymph tissue. The most notable symptom is swelling of lymph nodes in your neck,…

  • Non-substance Addiction

    A non-substance addiction is sometimes called behavioral addictions. It can include gambling, sex, shopping, the internet and more.

  • Nonalcoholic Fatty Liver Disease

    Nonalcoholic fatty liver disease (NAFLD) is a buildup of fat in the liver. This common condition can be harmless but…

  • Nosebleeds

    A nosebleed is blood loss from the tissue that lines your nose. It most often occurs in only one nostril,…