Varicose veins getting worst.having black spots on my leg already spreading.is this serious?

Varicose veins: Varicose veins are due to underlying venous insufficiency or reflux, which will never improve or go away on its own, and can only get worse. So down the road it could become serious, if not already. You should be seen by an experienced vein specialist, who can determine the cause of your problem, and the best way to treat it. The good news is that almost all vein treatments are minimally invasive.

Maybe: Skin discoloration can be a sign serious vein problems, usually dark brown, or dark red. These skin lesions can lead to ulceration. You need to have a duplex ultrasound and work up by someone experienced in vein disease. Once treated, many times the skin will become healthy again, and sometimes even become more normal in appearance.

Venous Stasis Stains: Venous stasis disease involves stagnation of the venous blood flow, resulting in a pooling of blood in the lower extremities. Iron is deposited into the skin resulting in brown staining of the skin. This can result in breakdown of the skin to frank ulceration with years of stasis. Compression therapy is very helpful along with laser closure of the varicose veins. Ultrasound review is a must.

Could be: It sounds as though you are starting to develop evidence of chronic venous insufficiency with venous hyperpigmentation, as the others have discussed very nicely. The first thing you need to do is to get yourself into a pair of prescription compression stockings, as dr. Albers said. I would recommend 30-40 mmhg. You also need to see a vein specialist for an evaluation and treatment recommendation.