We often do not give our thumb much thought as an important digit. In the age of keyboards and touch screens, the thumb may not seem as useful but when afflicted with pain or restricted movement, we then appreciate the significance of this stubby first finger. Thumb pain may arise due for a different reasons and be accompanied by other symptoms like swelling and restricted movement.
What is thumb pain?
Thumb pain is where there is discomfort or pain in the thumb. This may or may not be accompanied by pain in the other fingers, which may be broadly referred to as finger pain. However, the term finger pain may also include thumb pain. With the hand working for long periods during waking hours and making close contact with the environment on a constant basis, the thumb is naturally prone to injury.
However, various diseases and disorders can affect the thumb and thereby lead to pain. The severity of these conditions can vary and severe pain may not necessarily indicate a severe condition. It is therefore important to have a painful thumb assessed by a medical professional. Early diagnosis of certain conditions can greatly improve the outcome and prevent the onset of complications.
Thumb pain is a symptom on its own and a host of other symptoms may arise along with it. These symptoms may depend on the underlying cause. It includes:
- Thumb swelling
- Redness, paleness or a bluish-purple color of the thumb.
- Heat from the thumb.
- Scabs or wounds which may bleed or ooze a discharge.
- Restricted thumb movement.
Sometimes thumb pain occurs on its own with no other symptoms. The pain, as well as other symptoms, may only affect one thumb (unilateral) or both thumbs (bilateral).
Causes of Thumb Pain
There are a host of causes of thumb pain. Most are acute in nature and often related to trauma or strain. Sometimes chronic conditions like osteoarthritis can also be responsible for the pain that is usually persistent with episode of acute flareups. Some of the more likely causes of thumb pain has been discussed below.
Injury to the thumb is one of the more common causes of thumb pain. It can occur with blunt or sharp force trauma, exposure to harsh chemicals, burns and electromagnetic radiation. Injuries may be superficial, affecting only the skin and underlying tissue, or deep where it involves the tendons, muscles, ligaments and even the bone. Overuse of the thumb can also lead to repetitive stress injuries.
The thumbs are bony structures with overlying soft tissue like tendons, ligaments, connective tissue and skin. In severe injuries the bone of the thumb may be fractured. These fractures can vary from a crack in the bone to a complete break in the bone. Sometimes the broken portion can pierce and protrude through the skin and may sever underlying soft tissue like tendons in the process.
Infections of the thumb may vary from superficial to deep. Superficial bacterial infections like impetigo or cellulitis are usually painful. Other superficial infections like those caused by fungi (hand fungus) are usually itchy but not painful. In severe cases the infection can affect deep structures like the bone (osteomyelitis) which is very serious. An abscess, also referred to a boil, can also cause pain.
Muscles and Tendons
A collection of muscles are responsible for movement of the hand. If the thumb muscles or its tendons are injured or strained it will lead to thumb pain. Overuse is one of the common causes especially if a person is not conditioned for a specific thumb related action. Inflammation of the muscle is known as myositis and when the tendon is involved it is known as tendonitis. Sometimes the tendon may tear which can be very painful.
There are two joints in the thumb, one at the base of the thumb and the other other midway. As with other joints it can be afflicted with a host of conditions. This may also involve surrounding structures like the ligaments which supports joints. Osteoarthritis of the thumb is where the cartilage lining the bone at the joint becomes worn out.
Rheumatoid arthritis is where the joint lining becomes inflamed due to autoimmune factors. Gouty arthritis arises when uric acid crystals form in the joint. Septic arthritis and traumatic arthritis are other types of joint problems. Apart from arthritis, the bones may become dislocated where it slips out of the normal alignment at the joint.
The nerve carry pain signals and if injured, diseased or abnormally stimulated it may be perceived as thumb pain despite there being no other thumb problem. Carpal tunnel syndrome (CTS) is a common condition where the median nerve is compressed as it passes through the wrist. Although tingling and numbness along with weakness are usually present, there may also be pain in the thumb.
The nerve can be injured, compressed or damaged anywhere along its course. Compression of the nerve at the point where it exits the spinal cord at the level of the neck can also cause pain. This may occur with a herniated or bulging disc. Other nerve problems that may arise includes diabetic neuropathy where long term and poorly controlled diabetes mellitus causes nerve irritation and damage.
Impaired blood flow to the hand and specifically the thumb can also cause pain. This may occur with conditions like peripheral arterial disease (PAD) where the artery is narrowed and blood flow is reduced. A blood clot can cause an obstruction of the blood flow. Reduced blood flow leads to ischemia and initially there is pain. In Raynaud phenomenon the blood vessel becomes very narrowed due to a spasm and the blood flow is also drastically reduced.
Apart from skin infections like impetigo, there are various other skin diseases that may also cause thumb pain. It is usually inflammatory skin diseases like contact dermatitis that can present with pain. Any break in the skin can also lead to pain. This is usually related to trauma like a cut but can also arise with skin diseases that severely compromise the integrity of the skin.