You may have itchy skin over certain small areas, such as on an arm or leg, or over your whole body. Itchy skin can occur without any other noticeable changes on the skin. Or it may be associated with:

• Redness
• Bumps, spots or blisters
• Dry, cracked skin
• Leathery or scaly skin

Sometimes itchiness lasts a long time and can be intense. As you rub or scratch the area, it gets itchier. And the more it itches, the more you scratch. Breaking this itch-scratch cycle can be difficult.

Causes of itchy skin include:

• Skin conditions. Many skin conditions itch, including dry skin (xerosis), eczema (dermatitis), psoriasis, scabies, burns, scars, insect bites and hives.
• Internal diseases. Itchy skin can be a symptom of an underlying illness. These include liver disease, kidney failure, iron deficiency anemia, thyroid problems and certain cancers, including multiple myeloma and lymphoma.
• Nerve disorders. Conditions that affect the nervous system — such as multiple sclerosis, diabetes, pinched nerves and shingles (herpes zoster) — can cause itching.
• Psychiatric diseases. Examples of psychiatric diseases that can cause itchy skin are anxiety, obsessive-compulsive disorder and depression.
• Irritation and allergic reactions. Wool, chemicals, soaps and other substances can irritate the skin and cause itching. Sometimes the substance, such as poison ivy, parasites or cosmetics, causes an allergic reaction. Also, reactions to certain drugs, such as narcotic pain medications (opioids) can cause itchy skin.
• Pregnancy. During pregnancy, some women experience itchy skin.

Sometimes the cause of the itching can't be determined.

Itchy skin that lasts more than six weeks (chronic pruritus) can affect the quality of your life, for example, by interrupting your sleep and causing anxiety or depression. Prolonged itching and scratching may increase the intensity of the itch, possibly leading to skin injury, infection and scarring.