Find possible causes of numbness or tingling in hands based on specific factors. Check one or more factors on this page that apply to your symptom. Numbness or tingling. 1  Affects both hands. 2  Affects one hand.  Is intermittent.
These cells produce melanin, the substance that gives skin its color. Skin with too much melanin is called hyperpigmented skin. Skin with too little melanin is called hypopigmented skin. Pale skin areas are due to too little melanin or underactive melanocytes. Darker areas of skin (or an area that tans more easily) occurs when you have more melanin or overactive melanocytes. Bronzing of the skin may sometimes be mistaken for a suntan.
Melanoma is a malignant type of skin cancer caused by the uncontrolled growth of melanocytes. It spreads rapidly to other body parts such as liver, lungs, brains, and bones, usually in five stages. As to how fast does melanoma spread, the rate of growth is unpredictable.elanoma is a malignant type of skin cancer caused by the uncontrolled growth of melanocytes. It spreads rapidly to other body parts such as liver, lungs, brains, and bones, usually in five stages. As to how fast does melanoma spread, the rate of growth is unpredictable.