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.
Hypothyroidism, often called underactive thyroid or low thyroid and sometimes hypothyreosis, is a common disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone. It can cause a number of symptoms, such as poor ability to tolerate cold, a feeling of tiredness, and weight gain. In children, hypothyroidism leads to delays in growth and intellectual development, which is called cretinism in severe cases.