What is intermittent claudication and how common is it?
Atherosclerosis may cause narrowing or blockage in the arteries of the leg causing two very characteristic types of pain: intermittent claudication and ischaemic rest pain.
Claudication is derived from the Latin word for 'limp' but is now commonly used for the pain or discomfort associated with exercise. The level and extent of the arterial disease determines the severity of the symptoms (i.e. the amount of exercise needed to induce pain) and the location of the pain. Lesions in the femoral and popliteal arteries cause calf pain whereas lesions in the aorta and iliac arteries cause cramping in the buttock, hip and thigh.
At rest there is enough blood flow to feed the muscles and therefore no pain is experienced. After a certain amount of exercise the blood flow through the narrowed or blocked segments (the blood flows through smaller vessels called 'collateral' which bypass the blockage) is not enough to meet the demands of the muscles. The muscle metabolism then produces substances (including lactic acid) that cause the classic cramping and pain. This pain goes away after resting for a short while - long enough for the blood flow to catch up and washout these substances.
In addition to this haemodynamic problem, over time the disease affects the muscle neurological and metabolic function, leading to impairments in muscle performance and patient functional status.
The exact size of the problem in terms of number of people affected is difficult to estimate as many people do not consult their doctor. The incidence increases with age. The Rose questionnaire (designed to detect intermittent claudication by postal survey) suggests a prevalence of 0.4% - 14.4% in the population. As an approximation, 5% of men over the age of 50 years suffer from intermittent claudication.
The main risk factors for the development of intermittent claudication are:
 | Male gender |
| Age |
| Diabetes |
| Smoking |
| High blood pressure |
| High cholesterol |
| High fibrinogen (clotting substance in blood) |
Alcohol has a protective effect. Of course too much is bad for you !!