It can be difficult to make a<unk>  diagnosis since there are a variety of symptoms that a person can have, also family history and a physical examination are important. The physical exam may be different depending on the type of<unk> . In the case of a peripheral<unk>  the physical exam consists in checking the blood flow in the legs.
Vascular disease
Precancerous condition
Hematologic disease
Malignancy
Degenerative disease
Diathesis 
Nerve injury
Neuromuscular disease