Diabetics have to be cautious of symptoms that gradually arise, no matter how vague, as it may be the first indication of a complication. The legs are one of the parts of the body that are commonly afflicted with diabetic complications and pain is sometimes the first symptom. It is therefore important to understand why leg pain occurs in diabetics and how to differentiate pain due to a diabetic complication from leg pain that may also affect non-diabetics.
The blood glucose levels need to be regulated all the time to ensure that there is an adequate supply of glucose for all cells. Insufficient glucose means that cells cannot produce the energy needed for life-sustaining processes. High blood glucose levels can be detrimental since it can damage cells, nerves and blood vessels. Therefore it is important that the body maintains the blood glucose levels within a narrow range.
This glucose regulation involves a combination of mechanisms, the most important of which is the action of the hormones insulin and glucagon. Insulin lowers the glucose levels when it rises too high and glucagon increases it when the levels drop too low. With diabetes, the pancreas either cannot produce insulin or the cells in the body do not respond to insulin. As a result the glucose levels are higher than normal.
Leg Symptoms In Diabetics
Diabetic foot is a broad term for many of the diabetes-related complications that affect the feet. These complications may be continuous with those of the lower leg. Pain is a symptom and the reason why it occurs is explained below. However, there can also be other leg symptoms which may or may not be related to the pain. These symptoms can affect only one leg or may affect both legs.
- Muscle cramps along with pain after physical activity of the legs.
- Open sores (ulcers) that do not heal or are difficult to heal.
- Tingling, prickling, burning and/or numbness.
- Weakness of the leg muscles.
- Coldness of the legs.
- Change in the color of the legs – paleness, bluish tinge, dark red to purple and black patches.
- Shiny skin on the legs and loss of hair or slow hair growth.
- Weak pulse or sometimes no pulse.
Causes of Diabetic Leg Pain
The elevated blood glucose levels gradually damage cells in the body. However, some tissues appear to be more sensitive than others. The blood vessels and nerves in particular are easily damaged by high blood glucose levels. These effects are more pronounced in long term diabetes, especially in cases where the diabetes has been poorly managed.
Therefore understanding the nature of the blood vessel and nerve damage in diabetes is necessary to understand why leg pain may be occurring. It is also important to remember that diabetes can affect a host of other organs and systems in the body which may contribute to leg pain, like weakening of the immune system which increases the risk of infections.
Sometimes the leg pain in diabetics may not occur due to the diabetes specifically. Instead the leg pain may occur for the same reasons as it would occur in any other person, whether they are a diabetic or not. Muscle strain, injury and overuse are some of the reasons for leg pain that does not depend on diabetes.
Impaired Blood Circulation
High blood glucose levels affect the arteries in several ways. It can eventually lead to a condition known as peripheral arterial disease (PAD). Here there is narrowing of the arteries that carry oxygen and nutrient rich blood to the legs. Initially there may be no symptoms. Eventually some of the symptoms mentioned above, including leg pain, arises only when the legs are exerted like when running or climbing stairs.
The reduced blood supply to the legs leads to tissue injury known as ischemia. It also hampers healing due to the reduction of resources like oxygen and nutrients. Furthermore the reduced blood supply also hampers the immune response to infections. Along with the nerve damage discussed below, there is a greater risk of injuries and infections with poor wound healing and impaired immune response.
Nerve Damage and Dysfunction
The damage to nerves due to the high blood glucose levels (diabetic neuropathy) has a host of effects. Firstly sensory nerve conduction is impaired meaning that a person loses normal sensation. Sometimes there may be numbness where there is no sensation. Ultimately it leads to injuries which are not even felt. Infections may set in and become extensive without a person experiencing the early signs and symptoms like pain when medical treatment would be the most effective.
Secondly some of these nerve fibers control the size of the blood vessels. This effect is not under voluntary control and is part of the autonomic nervous system. It affects regulation of blood flow through the legs which may already be complicated with peripheral arterial disease. Thirdly, the irritation of the nerves due to diabetes can also lead to neuralgia (nerve pain) even when there is peripheral arterial disease, ulcers or infections.
Treatment of Diabetic Leg Pain
The treatment and management of leg pain in diabetics depends on the cause of the pain. Control of blood glucose levels is essential to limit the progression of the condition. This involves a combination of dietary and lifestyle measure as well as anti-diabetic medication and insulin if necessary.
- Antibiotics may be needed to treat infections.
- Anticoagulants may be needed to prevent blood clot formation in the narrowed artery.
- Cholesterol-lowering medication to reduce plaque formation in the artery walls.
- Angioplasty and stenting or bypass surgery to restore blood flow in the leg.
- Wound care with removal of dead skin (debridement).
These are just some of the measures that may help with treating diabetic leg pain. However, there is not always a single solution that will resolve the pain. Any therapy should be directed at the underlying causes – restricted blood flow and nerve damage caused by elevated blood glucose levels. Lifestyle changes, exercises and other therapies may also be helpful to restore blood flow to the area and control blood glucose levels which can ultimately reduce the pain.