Shingles is caused by the same virus that causes chickenpox, although shingles is not contagious. The virus can reawaken from being dormant for years or decades and attacks the nerves and causes a painful rash on the skin. Shingles can also attack internal organs and cause serious symptoms and complications that require medical evaluation and prompt treatment.
Swelling of the lymph nodes of the neck, under the arms and in the groin may result from the body's immune response to the virus.
According to the Mayo Clinic, shingles can cause abdominal pain and tenderness or an upset stomach.
Post-herpetic neuralgia results from damaged nerve fibres from shingles attacks and can cause feelings of intense pain throughout the body at the slightest touch.
Shingles can cause blisters or lesions in the mouth, which may produce pain and problems with eating and swallowing.
Encephalitis is inflammation of the brain, which is a serious and potentially life threatening condition. It may be caused by shingles attacking the nerves around the brain.
If shingles attacks the nerves of the ears, partial or full hearing loss in one or both of the ears may occur.
Vision problems including blindness may be caused if lesions from shingles get on or around the eye or if shingles attacks the optic nerve.