What is lump?

Most swollen glands or lumps under the skin aren't cause for concern. The glands (lymph nodes) on either side of the neck, under the jaw, or behind the ears often swell when you have a cold or sore throat.

More serious infections may cause the glands to get bigger and become very firm and tender. Glands can also swell and become tender after an injury, such as a cut or bite, or when a tumor or infection occurs in the mouth, head, or neck.

Swollen glands and other lumps under the skin can be caused by many different things, including illness, infection, or another cause.

Infections

Swollen glands often occur when the body fights infections from colds, insect bites, or small cuts. More serious infections may cause the glands to get bigger and become firm, hard, or tender. Examples of such infections include:

• Bacterial infections, such as:
  • Strep throat. It's caused by streptococcus bacteria.
  • A boil (abscess), similar to a large pimple. A boil may form when a hair follicle or the skin gets infected. A sweat gland abscess may form one or more lumps in the armpit that look like boils.
• Viral infections, such as:
  • A viral infection of the skin (molluscum contagiosum) that causes small pearly or flesh-colored bumps.
  • Measles, rubella, chickenpox, or mumps.
  • AIDS (acquired immunodeficiency syndrome). It develops in the late stage of HIV (human immunodeficiency virus) infection. This virus attacks the immune system. It makes it hard for the body to fight off infection and some diseases.
  • Mononucleosis (Epstein-Barr virus) or cytomegalovirus (CMV). These viruses cause fever, sore throat, and fatigue.
• Other infections, such as:
  • Lyme disease. This is an infection that's spread by certain types of ticks.
  • Syphilis. It's a sexually transmitted infection.

Noncancerous (benign) growths

Types of noncancerous (benign) growths, which are usually harmless, include:

• A lipoma. This is a smooth, rubbery, dome-shaped lump that you can easily move under the skin.
• A cyst. It's a sac of fluid and debris that sometimes hurts.
  • Cystic lesions from acne are large pimples that occur deep under the skin.
  • Branchial cleft cysts are found in the neck. They don't usually cause problems unless they get infected. These cysts are most common in teens.
  • A skin cyst often appears on the scalp, ears, face, or back.
  • A ganglion is a soft, rubbery lump (a type of cyst) on the front or back of the wrist.
• Tonsillitis. It may also cause swelling in the neck.
• A salivary gland problem, such as inflammation, a salivary stone, an infection, or a tumor.
• An inflammation of fatty tissue under the skin (erythema nodosum) or overgrown scar tissue (keloid).

Hernias, aneurysms, or nodules

Hernias and aneurysms are bulging sections in a muscle or blood vessel. A nodule is usually a growth on a gland. A hernia, aneurysm, or nodule may be felt under the skin. But you may not be able to see it. These types of lumps may need to be checked by a doctor.

• An inguinal hernia is a soft lump in the groin or near the navel. It may be more visible when you cough. Hernias that disappear when you press on them may not need any treatment. Hernias that don't disappear when you press on them may be more serious and need medical treatment.
• A bulging section in the wall of a blood vessel (aneurysm) may feel like a throbbing lump in the belly, in the groin, or behind the knee. It can cause serious problems if it involves the blood vessels in the brain or the belly. Aneurysms may be a medical emergency and may require care right away.
• A thyroid nodule is an abnormal growth on the thyroid gland. An enlarged thyroid gland (goiter) is in the neck just below the Adam's apple.

Swelling caused by cancer

A lump caused by cancer is usually hard, irregularly shaped, and firmly fixed under the skin or deep in tissue. They usually don't cause pain. But some types of cancerous lumps are painful. Most lumps aren't caused by cancer.

Other causes

Swelling may also be caused by:

• A side effect of a medicine, such as phenytoin (Dilantin).
• Other medical conditions and diseases, such as lupus, myalgic encephalomyelitis/chronic fatigue syndrome, or rheumatoid arthritis.