Thumb joint pain at the base of the thumb is most often osteoarthritis of the joint where the thumb meets the wrist. It typically hurts on pinching, gripping and twisting: opening a jar, turning a key, holding a pen. Pain in the finger joints, a finger that clicks or locks, or pain running along the thumb tendons each point somewhere different, and each is managed in its own way.

Why the base of the thumb wears out

The joint at the base of the thumb is the carpometacarpal joint, usually shortened to the CMC joint, and it sits deep in the fleshy part of the hand where the thumb meets the wrist.

It is shaped like a saddle, with two curved surfaces sitting across each other. That shape lets the thumb swing, rotate and press in almost any direction. The trade off is wear: a joint that moves that freely while carrying that much pinch force is the one most likely to develop osteoarthritis in the hand.

Arthritis at the base of the thumb is far more common in women than in men, and it becomes more common after the age of 50.

What thumb base arthritis feels like

A deep ache right at the base of the thumb, worse with pinch and load rather than with movement on its own. The triggers are familiar: opening jars, turning a key in a stiff lock, pinching a lid, wringing out a cloth, and long stretches of texting or scrolling.

Over time the joint can look different, with a visible squaring off at the base of the thumb where the bone shifts slightly outward. Pinch grip weakens, so things slip out of the hand.

Thumb base arthritis or De Quervain’s tenosynovitis?

These two are confused constantly. Arthritis hurts right at the joint and is worse with pinch and load. De Quervain’s tenosynovitis, irritation of the sheath around the tendons running into the thumb, hurts further along the thumb side of the wrist and is worse when thumb and wrist move together, such as lifting a kettle. A separate guide covers wrist pain by location.

Trigger finger and trigger thumb

Trigger finger is a tendon problem, not a joint problem. The tendon that bends the finger runs through a snug tunnel in the palm, and when the tendon or its sheath thickens it catches as it passes through.

You feel it as a click or a snap when the finger bends or straightens. In some cases the finger locks bent and has to be straightened with the other hand. It is usually worst first thing in the morning and eases as the hand warms up, and there is often a tender lump in the palm at the base of that finger. It is more common in people with diabetes.

Arthritis in the finger joints: two different patterns

Osteoarthritis in the fingers affects the middle and end joints. It produces firm, bony, knobbly swellings: Heberden’s nodes at the joints nearest the fingernails, and Bouchard’s nodes at the middle joints.

Inflammatory arthritis behaves differently. It typically affects the knuckle joints, tends to appear on both hands in a similar pattern, and causes soft, puffy swelling with morning stiffness lasting more than an hour.

The difference matters because it changes who you should see: inflammatory arthritis needs assessment by a rheumatologist, and the earlier the better.

Hand pain by location: a quick guide

• Base of the thumb: osteoarthritis of the CMC joint. Worse with pinching, gripping and twisting.
• Thumb side of the wrist: De Quervain’s tenosynovitis. Worse when the thumb and wrist move together.
• Middle and end finger joints: finger osteoarthritis, often with bony knobbly swellings.
• Knuckles on both hands: possible inflammatory arthritis, with prolonged morning stiffness.
• Palm, with a finger that catches or locks: trigger finger.
• A numb patch rather than an ache: a nerve problem, not a joint problem.
• The whole hand, stiff every morning: worth an assessment for inflammatory arthritis.

For tingling and numbness, our guide to numbness in the fingers maps which fingers point to which nerve.

What helps day to day

Reducing the pinch force your thumb has to produce is the most useful change, and it is mostly about equipment rather than effort.

Build up the grips. Thicker pens, foam tubing slipped over tool handles, and chunky handled knives and peelers all need less pinch to control.

Use leverage. A jar opener, a lever tap, an electric tin opener and a key turner take the twist out of the tasks that hurt most.

A thumb spica splint, which holds the thumb and wrist still while leaving the fingers free, can help settle a flare, and many patients find it most useful overnight or during a heavy task.

Heat before activity often loosens a stiff hand, and pacing helps: break long jobs into shorter stretches and swap hands where you can.

Treatment options for thumb joint pain

Thumb and hand pain is managed in steps. The first are the ones above: changing how you grip, splinting through flares, and hand therapy, where a physiotherapist or occupational therapist fits a splint and strengthens the muscles supporting the thumb.

When that is not enough, an interventional pain clinic can add more. Ultrasound lets a physician see the small joints and tendon sheaths of the hand, so an injection is guided to the exact spot rather than placed blind. That applies to the thumb base joint and to trigger finger.

Hyaluronic acid injections, which add a lubricating gel to a worn joint, are an option for selected arthritic joints, and platelet rich plasma (PRP) is considered in selected cases. Where numbness is the main problem, the focus shifts to the nerve, as our page on nerve entrapment syndromes explains.

Surgery sits further along the ladder for advanced thumb base arthritis and for trigger finger that keeps coming back, so the options do not stop there.

Warning signs that need urgent care

Seek medical attention promptly if you have:

• A hot, red, swollen joint with fever, which can indicate infection and needs same day care
• A finger locked bent that you cannot straighten at all
• A sudden inability to bend or straighten a finger after an injury, which can mean a torn tendon
• Rapidly progressive swelling in several joints, with morning stiffness lasting over an hour
• Numbness with visible wasting of the muscle pad at the base of the thumb
• Any hand injury that leaves a finger or the hand looking deformed

Frequently asked questions

How do I know if my thumb pain is arthritis?

Arthritis at the base of the thumb aches right at the joint and is worse with pinch and load, so jars, keys and lids are the usual complaints. Tendon pain sits further along the thumb side of the wrist. An examination, and sometimes an X-ray, confirms which it is.

What helps base of thumb pain at home?

Thicker grips on pens, tools and kitchen items reduce the pinch force the joint handles. Jar openers, lever taps and key turners remove the twisting. A thumb spica splint can settle a flare, heat often loosens a stiff hand, and pacing long tasks avoids overload.

Does trigger finger go away on its own?

Sometimes it settles, particularly if it is mild and recent. When the catching persists, or the finger locks and has to be straightened with the other hand, it usually needs treatment. Options include splinting, an ultrasound guided injection into the tendon sheath, and surgery for cases that keep returning.

Can using a phone cause thumb joint pain?

Long stretches of texting and scrolling can aggravate an already worn thumb joint, because the thumb is held in a pinch position and moved repeatedly. It is more often a trigger for symptoms than the cause. Holding the phone in the whole hand and typing with a finger takes the load off.

This article is general information, not medical advice. It cannot diagnose your pain. If your symptoms are new, worsening, or worrying you, speak with your family doctor or contact us for an assessment.

Talk to us about thumb and hand pain

If the base of your thumb has hurt for months and splinting and hand therapy have not helped, an assessment can confirm which structure is involved. Silver Pain Centre in Toronto offers ultrasound guided injections for the small joints and tendons of the hand, and most services are covered by OHIP with a physician referral.

Ask your family doctor to send a physician referral, or use our self referral form to start without waiting for one.