Arteries are blood vessels that carry oxygenated blood with the exception of pulmonary artery, which carries deoxygenated blood. In cold conditions arterioles contract, reducing the quantity of blood and heat reaching the skin surface. When Raynaud's disease occur the contraction of the arteries is so intense that it deprives the tissues of the toes or fingers from blood flow and thus from oxygen, making them appear white and pale. This contraction of the artery further reduces the amount of heat radiated in the skin surface making the affected areas feel cold and numb. The contraction is followed by the dilation of the blood vessels that carry deoxygenated blood, the veins and capillaries. It is this deoxygenated blood that gives the affected area a bluish color. When the fingers or toes are warmed the arteries expand and the blood starts to flow normally making them red. The dilation of the artery results to heat being radiated on the surface of the skin and the patient may experience warming up of the fingers or toes.
Other cases of Raynaud's disease may cause the development ulcers. The simple treatment of Raynaud's disease involves warming and proper covering of the hands and feet but it can in other cases be treated through medication e.g. the use of Nitroglycerine paste. However where gangrene has developed, surgery will be required to remove the dead or decayed tissues.