Swollen legs: causes
Possible causes of edema are already listed in the articles "Fat legs due to venous diseases" and "Fat legs: infections, diseases of the lymphatic vessels and organs". In addition to the causes for swollen legsThere are numerous other possible triggers that can cause excessive fat or fluid build-up in the legs.
Diabetes and fat legs
Among the possible other causes of the swollen legs, diabetes must be mentioned first, with the vascular damage occurring in the course of diabetes being the main trigger. So-called ischemic edema (fluid deposits due to circulatory disorders), which usually appear as swelling on both legs, can sometimes be seen in diabetes patients. In principle, diabetes can cause swelling in the legs in various ways, but in most cases damage to the vessels caused by high blood sugar levels plays an important role. For example, diabetics tend to develop arteriosclerosis due to the usually existing high blood pressure.
High blood sugar is also a risk of developing thrombosis. Many diabetics also suffer from impaired kidney function, which can also lead to fluid deposits in the legs. In addition, the swelling on the legs may also appear as complications from diabetes-related damage to the nerves, skin ulcers and infections. The swelling can also be part of the so-called diabetic foot syndrome, a serious complication of diabetes, which often requires an amputation of the foot.
Edema due to metabolic disorders
General metabolic disorders are another possible cause of fat legs. The metabolic disorders prevent impaired protein, water and mineral balance, the orderly fluid exchange in the organism, which can lead to fluid accumulation in the legs. However, the metabolic disorder may also manifest itself as a fat distribution disorder, which for example results in excessive fat deposits on the hips, the so-called lipedema. The legs are often particularly sensitive to pain or pressure and are prone to hematomas. The altered adipose tissue also tends to increase fluid retention as the disease progresses due to impaired capillary function. In addition, due to the increased susceptibility to inflammation, the lymphatic system can be affected over time, which further promotes the development of edema on the legs.
Thick legs due to joint inflammation
Swelling of the leg in the area of the joints (usually knees or ankles) can also be traced back to joint inflammation. The most well-known form of inflammatory joint diseases is arthritis. The affected joints appear red, show overheating and swell (so-called joint effusion). Most often, arthritis is accompanied by pain in the joints, which increases under stress. The general ability of the joints to move and exercise is also restricted.
Those affected tend to be careful when the affected joint is loaded or moved as little as possible. The arthritis-related swellings on the joints of the legs remain rather inconspicuous, but they are relatively easy to feel at the knee or ankle. Arthritis can be attributed to rheumatic diseases, past infectious diseases (e.g. Lyme disease) or metabolic diseases. Acute symptoms caused by bacteria in the joints are also possible, whereby this so-called purulent, bacterial arthritis immediately requires medical care due to the considerable health risk.
Furthermore, chronic inflammation of the joints can form cysts, which are referred to as the so-called Baker's cyst in the area of the knee joint. The inflammatory processes result in an increased production of synovial fluid, which causes an increase in pressure in the knee joint, which in turn can lead to protrusions of the joint capsule, which appear as a Baker's cyst. While the symptoms of Baker's cyst usually focus on the area of the knee, bursting or tearing of the cyst can cause swelling of the lower leg or the entire leg. If the Baker's cyst bursts, there is also the risk of the so-called compartment syndrome. The increase in pressure associated with the swelling leads to circulatory disorders and damage to the blood vessels, muscles and nerves. In the worst case, the consequences can be considerable neuromuscular damage and tissue death.
Swollen legs due to allergic reactions
Sudden leg swelling may also be due to an allergic reaction, which can be triggered by a variety of causes such as insect bites, certain foods or the ingredients of shower gel, creams and shampoo. Redness, swelling and itching of the skin are typical signs of an allergic reaction.
The most widespread are so-called contact allergies, which are due to skin contact with substances such as nickel, perfume, cobalt, formaldehyde, chromium. Contact allergies often affect people who come into contact with the relevant substances in their everyday work. So-called contact eczema is often the result of contact allergy. However, more serious allergic reactions are often the result of insect bites, food allergies or so-called inhalation allergens (allergens absorbed via the respiratory tract). In the case of allergic leg edema, the swelling is usually caused by the release of the messenger histamine, which influences the permeability of the blood vessels and thus causes water retention in the tissue.
Side effects of medication and alcohol
Fat legs can also be the result of improper or long-term use of medications, such as certain anti-inflammatory drugs, high blood pressure medications, or medications containing cortisone. Medications that have an influence on the vessels and the metabolism, in particular, may bring the pressure ratio of the body fluids out of balance and thus cause fluid accumulation in the legs. The swellings mostly appear in the area of the feet and ankles, but the whole leg can also be affected at times.
The medications associated with leg edema also include hormone supplements (e.g. menopause hormone therapies, contraceptives), hair restorer, laxatives and diuretics. The sometimes negative effect of diuretics and laxatives is based on an intervention in the water-salt balance. The prolonged, uncontrolled use or incorrect dosage of the medication brings with it considerable impairments to the water-salt balance, as a result of which the pressure conditions of the body fluids can get mixed up and fluid deposits can form in the legs. The possible effects of the medication on the protein and mineral concentrations in the body may also impair the removal of fluid from the tissues and thus promote the formation of edema.
While the medication can cause long-term consequences of swollen legs, alcohol can show an enlargement of the blood vessels immediately after ingestion, which can cause swelling of the feet and ankles. At the same time, urine excretion is increased and fluid is also released through the sweat glands. In addition, increased alcohol consumption causes long-term damage to the liver (alcohol is a cell poison), which in turn can cause swelling in the leg area.
Unhealthy habits, which can be the cause of fat legs, relate primarily to diet and physical activity. Physical and nutritional deficiencies can promote or even cause edema. A typical consequence of a lack of exercise is the impaired functioning of the cardiovascular system, which in turn has a negative effect on blood circulation and can therefore lead to swelling in the legs. A lack of physical activity combined with unhealthy eating habits also favors the development of overweight. The increased fat deposits and the associated vascular damage can also result in swollen legs.
With regard to the thick legs, a possible lack of protein plays a special role in the diet. Special proteins such as albumin have a significant influence on the regulation of the pressure ratios of body fluids. If there is a lack of the required protein substances, the balance of body fluids gets out of balance and between the cells, fluid accumulations form in the tissue. This phenomenon, also known as protein deficiency edema, can also be caused by a lack of protein intake through food.
Chronic malnutrition, eating disorders (e.g. anorexia) and a disturbed absorption of proteins via the intestine (e.g. chronic inflammatory bowel diseases) can sometimes trigger the swollen legs. These are often accompanied by a build-up of fluid in the abdominal cavity (hunger edema) and on the eyelid in the event of a diet-related protein deficiency. The protein deficiency can not only indicate nutritional deficits, but may also be due to the increased protein consumption of cancer or chronic inflammation. Therefore, a medical examination should urgently follow here to rule out more serious health risks.
Tumors and paralysis after a stroke
In general, cancer must be considered as a possible trigger for the swollen legs, but in the rarest cases a tumor is actually the cause of the fat legs. In tumors, the swelling of the legs is initially localized in the area of the actual cancer. The swelling is usually accompanied by pain and can lead to considerable damage to the surrounding tissue. Since the veins and vessels are also affected in this way, there is a risk of blood backlogging and the increased formation of edema in the further course of the disease.
One of the most common forms of cancer in the leg area is the development of bone cancer in the knee. In addition to the tumors, paralysis such as after a stroke is one of the rather rare causes of swollen legs. Due to the persistent muscle paralysis, edema develops over time, which can spread from the foot to the ankle and lower leg to the entire leg. (fp)
Diagnosis of swollen legs
Treatment of thick legs
Author and source information
This text corresponds to the specifications of the medical literature, medical guidelines and current studies and has been checked by medical doctors.
Dipl. Geogr. Fabian Peters
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- Mayo Clinic: Lymphedema - Symptoms & causes (accessed: October 7, 2019), mayoclinic.org
- Gerd R. Lulay: Secondary lymphedema: diagnosis and therapy still unsatisfactory, Dtsch Arztebl 2017, aerzteblatt.de
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