A common cause of pain at the base of the thumb and wrist — also known as "smartphone tenosynovitis"
In De Quervain's tenosynovitis the tendon sheath around the tendons that move the thumb becomes thickened and stiff, narrowing the tunnel the tendons run through. Despite the name, tissue studies show thickening and degeneration of the sheath rather than true inflammation.
It causes pain and swelling on the thumb side of the wrist, often worsened by smartphone use, typing, or lifting a baby.
It is especially common in women during pregnancy, the postpartum period, and around menopause.
Repetitive motion from phones, computers, holding a baby, or instruments stresses the tendons
Smooth gliding is lost and tiny injuries develop on the tendon surface
The swollen sheath squeezes the tendon, making every motion painful
If left untreated, catching and weakness can interfere with daily life
Early rest often relieves symptoms within 1–2 weeks. When a steroid injection is needed, the success rate is high. Even after surgery, patients usually return to daily activities within 1–2 weeks. Reviewing how you use your hands is key to preventing relapse.
When to see a specialist.
If pain lasts more than 1–2 weeks, doesn't respond to over-the-counter medication, or thumb movement keeps getting worse, please come in. A Finkelstein test plus ultrasound confirms the diagnosis, and an injection can often be performed the same day.