(a) Symptoms are your own description of your physical or mental impairment. If you are a child under age 18 and are unable to adequately describe your symptom(s), we will accept as a statement of this symptom(s) the description given by the person who is most familiar with you, such as a parent, other relative, or guardian. Your statements (or those of another person) alone, however, are not enough to establish that there is a physical or mental impairment.
(b) Signs are anatomical, physiological, or psychological abnormalities which can be observed, apart from your statements (symptoms). Signs must be shown by medically acceptable clinical diagnostic techniques. Psychiatric signs are medically demonstrable phenomena that indicate specific psychological abnormalities, e.g., abnormalities of behavior, mood, thought, memory, orientation, development, or perception. They must also be shown by observable facts that can be medically described and evaluated.
(c) Laboratory findings are anatomical, physiological, or psychological phenomena which can be shown by the use of a medically acceptable laboratory diagnostic techniques. Some of these diagnostic techniques include chemical tests, electrophysiological studies (electrocardiogram, electroencephalogram, etc.), roentgenological studies (X-rays), and psychological tests.