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.
Melanocytes are the cells that synthesize pigment. Through a series of enzymatic reactions these cells efficiently produce melanin pigment that determines skin color. Once it is formed, melanin is packaged into tiny vesicles called melanosomes. The melanocyte has tiny tentacles that it uses to transfer melanosomes to other skin cells. It is interesting to note that dark-skinned patients do not have more melanocytes but instead have melanocytes with more pigment producing power.