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.
Your bone marrow makes platelets. Problems can result from having too few or too many platelets, or from platelets that do not work properly. If your blood has a low number of platelets, it is called thrombocytopenia. This can put you at risk for mild to serious bleeding. If your blood has too many platelets, you may have a higher risk of blood clots. With other platelet disorders, the platelets do not work as they should. For example, in von Willebrand Disease, the platelets cannot stick together or cannot attach to blood vessel walls. This can cause excessive bleeding.