Why Do I Have Pain at the Base of My Thumb?

That sharp, localized ache at the base of your thumb can make even simple tasks like turning a doorknob, opening a jar, or texting painful. Since the thumb plays a central role in hand movement and grip, any discomfort at its base can seriously affect your daily life. 

The structure of the thumb is vital in determining the cause of the pain. The base of the thumb is where the thumb and the wrist meet, forming a special saddle-shaped joint called the CMC joint.

The thumb’s special joint enables it to perform a wide range of motion, although it also makes the thumb susceptible to some injuries and wear and tear.

Common Causes of Thumb Base Pain

Some main causes of pain at the base of your thumb include: 

• Basal Joint Arthritis

It is also called thumb osteoarthritis. Osteoarthritis is a condition that results in the cartilage in the joint losing its protective covering, and the bones end up rubbing against each other. 

The pain is usually a dull ache, although it may also become severe if one is trying to pinch or grip something. In addition, a bump or swelling is normally observed in the joint where the thumb and wrist meet.

• De Quervain’s Tenosynovitis

Another common cause, which involves the inflammation of the tendons on the thumb side of the wrist. This usually occurs due to repeated actions involving the thumb or the wrist, such as texting, typing, or lifting. 

The pain is usually most severe while making a fist or turning the wrist. There may also be tenderness over the tendons on the wrist side of the base of the thumb.

• Carpal Tunnel Syndrome

In this state, the median nerve gets compressed. The median nerve is the nerve that controls the sensation of the thumb. In the case of carpal tunnel, the sensation of burning that spreads to the thumb, or the weakness of the pinching power of the thumb, or the inability to hold objects, is usually observed.

• Trigger Thumb

This is when the tendon sheath surrounding the thumb gets inflamed, and the thumb snaps or pops when trying to straighten it. 

People with trigger thumb may notice sudden snapping or popping, and a small, sensitive bump develops on the palm side of the thumb at the base.

When to See a Specialist

It is also important to see an orthopedic hand specialist if the pain prevents you from doing your daily activities, the joint looks deformed, or there is a noticeable loss of strength in the thumb. This is where early treatment will make a huge difference in your health.

Depending on your condition, physical therapy or corticosteroid injections may be recommended to help prevent the need for surgery. Early treatment will ensure the health of the joint, allowing you to continue using your thumb comfortably for your daily activities.

Closing Note

Pain at the base of the thumb usually indicates an overused joint or wear of the protective cartilage. Whether the problem is arthritis or tendon inflammation, addressing it early is the best way to protect your hand’s function. 

Consult our board-certified orthopedic surgeon, Dr. Randy Y. Luo, MD, MBA, for any concerns regarding hand injuries. Call us today to book an appointment.