Why Does the Base of My Thumb Hurt? Common Causes Explained

Quick Answer: Pain at the base of the thumb usually comes from the carpometacarpal joint at the wrist end of the thumb, or from the two thumb tendons that run along the side of the wrist. Osteoarthritis, tendon irritation and repetitive gripping or phone use are the common causes. Most cases respond to load management and hand physiotherapy.

Reaching for a kettle, turning a key, or pinching a jar lid open — the base of the thumb carries more load than almost any other joint in the hand. When it starts to ache, ordinary tasks become the thing you notice most.

This guide from Elevate Physiotherapy explains what causes pain at the base of the thumb in 2026, why gripping makes it worse, and what treatment involves. You will learn which symptoms need medical review, and when to see a physiotherapist in Singapore.

Pain at the base of the thumb comes most often from one of three sources: osteoarthritis of the carpometacarpal joint, irritation of the two thumb tendons on the wrist side, or a strain of the small muscles and ligaments that stabilise the joint under pinch. Each has a different trigger and a different feel.

The carpometacarpal joint sits where the thumb meets the wrist, and it is shaped like a saddle so the thumb can swing across the palm. That mobility comes at a cost, because the joint is loaded every time you pinch. Wear at this joint is common from midlife onward and more common in women.

The second pattern involves the abductor pollicis longus and extensor pollicis brevis tendons, which run through a narrow sheath on the thumb side of the wrist. Sustained phone use is a recognised aggravator. A 2025 cross-sectional study of 202 young adults in the Indian Journal of Orthopaedics found daily screen time correlated with a positive Finkelstein test, the standard clinical sign for this tendon problem (Pomianowski et al., 2025).

Work-related loading matters here too. Singapore’s Ministry of Manpower recorded 317 work-related musculoskeletal disorder cases in 2025, up 27% from 249 the year before (MOM Workplace Safety and Health Report 2025). At Elevate Physiotherapy in Singapore, thumb pain is assessed alongside the wrist, forearm and neck, because pinch demand is rarely produced by the thumb alone.

Gripping hurts because the carpometacarpal joint has to resist several times the force you apply at the fingertip. A firm pinch on a jar lid translates into a much larger compressive and shearing load at the base of the thumb, which is why a small task can produce a disproportionate amount of pain.

The way that pain behaves tells you a great deal. Joint-related pain tends to be deep, aching and worst on twisting actions such as turning a tap or a key. Tendon-related pain tends to be sharper, sits slightly further towards the wrist, and flares when you lift with the thumb held out.

The table below sets out the patterns most often seen at Elevate Physiotherapy in Singapore, and what usually brings each one on.

Pattern	Where it is felt	Typical trigger
Carpometacarpal joint osteoarthritis	Deep ache in the fleshy base of the thumb, at the wrist crease	Turning keys, taps and jar lids; pinch-heavy tasks
De Quervain’s tenosynovitis	Sharp pain along the thumb side of the wrist, sometimes with swelling	Prolonged phone use, lifting a child, repetitive wringing
Trigger thumb	Catching or clicking at the palm side of the thumb	Repeated forceful gripping of tools or handles
Thumb ligament sprain	Pain on the inner edge of the thumb after a fall or a ball impact	A single incident rather than gradual overload
Referred symptoms from the neck or wrist nerves	Pain with pins and needles or numbness spreading into the fingers	Sustained postures; symptoms often worse at night

Reducing the pinch load for a few weeks, while keeping the thumb moving, settles most cases of base-of-thumb pain. Complete rest is rarely the answer, because the joint and tendons both need movement to stay tolerant of load. What helps is changing how you apply force rather than avoiding force altogether.

Practical steps for the first two to three weeks:

1. Swap pinch grips for whole-hand grips — carry bags in the crook of the elbow, use two hands on jars, and open taps with the palm rather than the fingertips.
2. Fit lever-style handles or silicone grips to keys, jar lids and kitchen tools so less force is needed at the thumb.
3. Hold the phone in the palm and type with the index finger for a week, instead of scrolling with the thumb.
4. Move the thumb through its full range several times a day, gently and without pushing into pain.
5. Use a short bout of heat before activity and a cold pack afterwards if the joint feels irritable.
6. Keep a simple note of which tasks flare it, so you and your physiotherapist have something objective to work from.

 

A soft thumb support worn during the aggravating task, rather than all day, often makes the first fortnight more manageable. A pharmacist or doctor can advise on what pain relief suits you. If the thumb is not easing after three to four weeks, arrange an assessment — Home Physiotherapy from Elevate Physiotherapy is available island-wide in Singapore for people who would rather be seen at home.

See a physiotherapist if thumb pain has not begun to improve within three weeks, if pinch strength is dropping, or if the same thumb flares every few months. Physiotherapy for thumb pain in Singapore focuses on rebuilding the muscles that stabilise the joint, adapting how you load it, and restoring pain-free pinch.

“More patients are arriving already ‘diagnosed’ by online searches and are anxious about scan findings,” says Winsen Citra, Principal Physiotherapist at Elevate Physiotherapy. “A lot of imaging findings are common and not necessarily the source of pain. Part of the job now is helping people interpret that information calmly and focus on what actually improves function.”

That caution applies squarely to the thumb, where X-ray changes at the carpometacarpal joint are frequently found in people with no symptoms at all. A 2025 multicentre randomised controlled trial in Osteoarthritis and Cartilage, involving 166 patients across 18 hand clinics, compared a thumb orthosis plus exercise therapy against an orthosis alone. Pain at three months was similar in both groups, though the researchers still favoured adding exercise on the basis of the secondary outcomes (van der Oest et al., 2025).

Seek medical review sooner if the thumb followed a fall or a forced sideways bend, if there is visible deformity, if the joint locks, or if numbness and pins and needles spread into the fingers. “It depends on the tissue and the load you’re returning to,” Winsen Citra adds, “but for most musculoskeletal injuries you should feel a meaningful change within a few weeks of consistent, correctly-loaded rehab.”

This article is for informational purposes only. Please consult a qualified healthcare professional. Individual results vary and no treatment outcome is guaranteed.

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