Swollen fingers or, medically speaking, dactylitis, are often uncomfortable and irritating. Usually, dactylitis isn’t a cause for concern, but it can be an underlying medical issue. Conditions that can cause the fingers to swell vary greatly in severity, ranging from mild and fleeting to potentially life-threatening.

Exercise

Many people find that their fingers swell after exercise. During a workout, the body adjusts blood flow to several areas. Delivery to the heart, lungs, and muscles increases, while parts like the hands receive less blood. In response, the blood vessels in the hands may expand, resulting in swollen fingers. Exercising also raises body temperature, and other systems try to counteract this by pushing blood towards the vessels closest to the surface to release heat through sweating. This is part of the process that makes a person sweat and may also cause hands and fingers to swell. Swelling in the fingers is more common when exercising in hot weather.

Salt Levels

Excess sodium or a lack of it can trigger swelling in the fingers. Normally, the body maintains a careful balance between sodium and water levels. As part of this balance, the kidneys filter the blood, pulling out excess sodium-filled fluid and passing it to the bladder. Consuming too much salt makes it difficult for the kidneys to do this properly, resulting in a buildup of fluid and eventual collection in the hands and fingers. Having too little sodium or too much water can cause similar issues.

Pregnancy

When a person is pregnant, nearly every part of their body experiences some degree of swelling. This begins in the first trimester with the release of the hormone progesterone, which tends to make the hands, feet, and face puffy. By the second trimester, the body is simultaneously creating and retaining more fluids. Often, the fluid settles in the feet and legs, though it may sometimes sit in the hands and fingers. Swelling generally increases throughout fetal development and continues up to delivery.

Infection

Certain infections can trigger swelling in the fat pads below the skin. Blistering distal dactylitis manifests as fluid-filled lesions within or on the fingers. Usually, this is due to a skin infection from Streptococcus or Staphylococcus bacteria. Infections like paronychia may cause inflammation in the area around the fingernail. Most infections are treatable with antibiotics.

Arthritis

Multiple forms of arthritis can cause dactylitis, as well. Generally, these conditions fall under the umbrella term spondyloarthritis. Almost one-third of people with this group of conditions also experience dactylitis. Psoriatic arthritis causes red, scaly patches of skin and swelling, especially of the hands and fingers. Sometimes, the swelling occurs before any other symptoms. Other arthritic conditions that may cause finger swelling are reactive arthritis and enteropathic arthritis.

Lymphedema

Lymph is an important fluid that carries fats, proteins, and other materials through the body. However, some people must undergo procedures to remove their lymph nodes, usually to treat cancer or another disease that has damaged the organs. Without lymph nodes, the lymph may begin to accumulate in certain parts of the body due to blockages, causing swelling known as lymphedema. While there is no cure, lymphatic drainage massage can help reduce swelling and prevent fluid retention.

Angioedema

Sometimes inflammation develops as part of an immune response. Angioedema occurs due to an allergic reaction and can cause swelling just beneath the surface of the skin. During an allergic reaction, the body releases histamine and other chemicals into the bloodstream. One of the effects of this process is swelling, though it may also cause pain, redness, and warmth. Angioedema usually affects the eyes and lips, though it can spread to the hands and fingers.

Carpal Tunnel Syndrome

Within the wrist is a tube that surrounds the median nerve and several tendons the carpal tunnel. Some people experience a narrowing of this tunnel that places pressure on the nerve, leading to a variety of symptoms. When a person with carpal tunnel sleeps without a brace or splint, they may move their wrist subconsciously. After waking up, their hands and fingers could be inflamed as a result.

Tuberculosis

Most people recognize tuberculosis as an infectious bacterial disease that primarily affects the lungs. Specifically, it causes inflammation that may lead to breathing issues, coughing up blood, and many other serious symptoms. Rarely, the inflammation spreads to their bones, causing the hands or feet to swell. In most cases, this affects only one side of the body.

Sickle Cell Disease

One of the most serious conditions that cause finger swelling is sickle cell disease. Most people have red blood cells with disc-like shapes, but people with this disease have sickle-shaped or curved red blood cells due to hemoglobin alterations and don’t carry oxygen as well. Among the first symptoms of sickle cell disease to develop is dactylitis. This is particularly true in children. Records show that hand and finger swelling due to blocked blood flow to the fingers may occur as early as six months. Dactylitis typically causes severe pain.