Although leg swelling is considered more common and often not associated with serious problem unless it occurs after a severe fall, the arms may be just as prone to swelling with certain conditions. It tends to be a greater cause for concern but sometimes the cause of arm swelling is not serious. At other times though swelling may indicate a fracture, blood clot in the arm, heart problem and even kidney disease.
Why does the arm swell?
Swelling anywhere in the body, either superficial or deep, is known as edema. It is usually due to a collection of tissue fluid that is not drained away effectively. Sometimes it can occur with pooling of blood. Localized swelling may also be due to an abscess or cyst. Swelling of the arm may affect the entire length of the upper limb or involve only the fingers, hands, forearm or upper arm.
Tissue fluid is constantly circulated with the arteries and veins carrying fluid to an area and draining it away. Any excess fluid remaining is then drained through the lymphatic system. Swelling is often indicative of inflammation where the blood vessel becomes leaky and excess fluid (without blood cells) empty into the tissue spaces at the site of injury. However, swelling can also occur with localized inflammation.
Sometimes swelling occurs throughout the entire body and this is known as anasarca. Swelling (edema) can be classified as pitting or non-pitting. Pitting edema is often indicative of a systemic cause like heart failure or kidney disease whereas non-pitting edema is typically seen with localized inflammation. In pitting edema, pressure on an area will leave an indentation that will take seconds to minutes to resolve while in non-pitting there is no persisting indentation with pressure.
Causes of Arm Swelling
Due to the variety of causes of arm swelling, it is often difficult to diagnose the underlying cause simply on the swelling alone. Accompanying symptoms may also provide an indication but the further diagnostic investigations may be necessary. Arm swelling that is progressively worsening, accompanied by severe pain, paleness or bluish tinge of the skin and/or discharge that is foul smelling should be investigated immediately. Never bandage a swollen arm as it cause worsen the swelling.
Mechanical or chemical injury to the arm can lead to swelling. This may be seen with a blow, penetrating injury and burns. Sometimes severe swelling may be indicative of a fracture even without pronounced deformity of the arm. Since the arm and specifically the hands are in constant contact with the environment, injuries are not uncommon. Often the swelling is accompanied by pain and redness over the affected area which is typical inflammation.
An infection of the arm may arise after penetrating injuries where microbes can gain entry to deeper tissue through a break in the skin. It can be superficial as in cases of impetigo or slightly deeper as with cellulitis or involve deep structures like the pone as is seen in osteomyelitis. Inflammation due to an infection is more frequently seen with bacterial infections often following an injury to the arm, damage or irritation of the skin in skin diseases or following insect bites and stings.
Irritants and Allergies
An allergy is a reaction to harmless substances (allergens) due to abnormal immune responses. Allergies only affect certain people who are hypersensitive. Irritants on the other hand can affect any person even without hypersensitivity. It arises as a result of a substance irritating the skin surface. The reaction is triggered by contact with the allergen or irritant. This can lead to allergic contact dermatitis or irritant contact dermatitis where the skin becomes red and itchy. There is swelling underneath the skin surface.
When the immune system attacks the body’s own tissues then it is known as an autoimmune disease. This causes inflammation at the site of the tissue undergoing the immune attack. There are many different types of autoimmune conditions that can lead to arm swelling but one of the more common conditions is rheumatoid arthritis. Inflammation of the joint lining leads to swelling at redness in and around the joint.
Any disruption to the draining of blood from the arm via the vein can lead to pooling of the blood and swelling of the arm. This is more likely to occur when the vein is blocked or compressed. The tissues in the arm can also become inflamed when there is insufficient oxygen supply often due to a disturbance in arterial blood flow. Apart from swelling it may lead to a pale to bluish discoloration of the arm with pain, tingling and numbness.
Apart from rheumatoid arthritis which was discussed under autoimmune conditions, other types of arthritis like post-traumatic arthritis, septic arthritis and gouty arthritis may also cause joint swelling on the upper limbs. Post-traumatic arthritis is joint inflammation due to injury to the joint. Septic arthritis is due to a joint infection. Gouty arthritis is a condition where uric acid crystals form in the joint spaces.
Strains and Sprains
Muscles and its tendons form the bulk of the upper limb tissue with ligaments that support the joints. When the muscles or tendons are overused or stretched it may lead to strain and sometimes even tears. Similarly ligaments may be stretched and even torn known as sprains. The ensuring inflammation may cause swelling of the affected portion of the upper limb. Spasm of the muscle can also cause a mass although this is not swelling.
The lymphatic vessels and lymph nodes can becomes blocked due to a manual obstruction or with inflammation and this prevents effective lymph drainage. It will present with swelling of the area which is normally drained by the specific channels. Lymphangitis is the term for lymph vessel inflammation while lymphadenopathy refers to enlarged lymph nodes. It can arise with injury, infections, certain autoimmune diseases and even cancer.
- Heart failure
- Kidney failure
- Liver failure
- Skin diseases – contact dermatitis, psoriasis and other inflammatory skin conditions
- Hypothyroidism (fat deposition)
- Cushing syndrome (fat deposition)