Pain in the lower back and hip radiating down the back of the thigh into the leg, initially attributed to sciatic nerve dysfunction (hence the term), but now known to usually be due to herniated lumbar disc compromising the L5 or S1 root.See: sciatic. (Contugno), Domenico Felice Antonio, Italian anatomist, 1736-1822.ain in the lower back and hip radiating down the back of the thigh into the leg, initially attributed to sciatic nerve dysfunction (hence the term), but now known to usually be due to herniated lumbar disc compromising the L5 or S1 root. See: sciatic. (Contugno), Domenico Felice Antonio, Italian anatomist, 1736-1822.
Dark spots are the result of the overproduction of melanin (skin pigment). It's not fully understood why dark spots develop, but aging and UV light exposureâeven exposure to artificial UV light, like the kind used in tanning bedsâare major causes. Dark spots can develop anywhere, but they are most likely to appear on the parts of the body that receive the most sun exposure, including: 1  The face. 2  The backs of the hands. 3  The shoulders. 4  The arms. 5  The back.
What Causes Dark Spots? There are several factors that lead to dark spot including genetics, pregnancy, UV light and skin diseases among others. Between the ages of 20 and 50, hormonal variances caused by stress, contraceptive pills, pregnancies, and menopause can also cause dark spots. Extreme exposure to sun light from sun baking accounts for some dark spots at later stages in life. Below the age of 20, acne can cause dark spots due to scarring and red marks left by the infection. Skin Diseases That Cause Dark Spots. Melasma: Itâs one of the commonest causes of grayish patches on the face.