What is repetitive strain injury (RSI)? Symptoms and causes

Quick answer: Repetitive strain injury (RSI) is an umbrella term for pain in muscles, tendons or nerves that is linked to repeated movement or overuse. It is not one diagnosis. The symptoms are pain, stiffness, weakness, tingling or numbness in the shoulders, arms, wrists or hands, and they usually start gradually. A doctor can tell you which condition you actually have, and that decides the treatment.

Health note: This page is general information, not medical advice. If you have numbness, weakness, night pain or symptoms after an injury, see a doctor first. When to see a doctor

What does RSI mean?

The NHS describes RSI as a term sometimes used for pain caused by repeated movement of part of the body. CCOHS, the Canadian occupational health agency, places it under the wider group of musculoskeletal disorders: painful problems of muscles, tendons and nerves that develop gradually from overuse.

So RSI is a label for a pattern, not a diagnosis. Two people with "RSI" can have quite different problems. That is why the same stretch or splint helps one person and does nothing for the next. Once a doctor finds the cause, the specific condition name tells you more than "RSI" does. The NHS also points out that arm pain is often a mix of factors, including ageing, and that many people do repetitive work for years without trouble.

What are the common symptoms of RSI?

The NHS says RSI can affect the shoulders, elbows, forearms, wrists, hands and fingers. Symptoms usually come on slowly and can include:

• pain that burns, aches or throbs
• stiffness and weakness
• tingling, pins and needles or numbness
• muscle cramps
• swelling

CCOHS describes how symptoms can progress. Early on, aching appears during work and fades overnight and on days off. In the intermediate stage it starts earlier in the day and persists at night. In the late stage aching, tiredness and weakness continue at rest and can disturb sleep. Early attention matters, because the first signs of pain, numbness or tingling mean the tissues need relief.

Which conditions can RSI turn out to be?

When a doctor examines you, RSI often becomes one of these conditions. Use the table to see how they differ, then read carpal tunnel vs tendonitis for more detail.

Condition	What it is	Typical signs
Carpal tunnel syndrome	Pressure on the median nerve at the wrist	Numbness, tingling and pain in the thumb and first fingers, often at night, and a weak grip
Tendinopathy, tendonitis	Irritated or inflamed tendon, usually after repetitive use	Pain and stiffness around the joint, worse with use
De Quervain's tenosynovitis	Irritation of two thumb tendons and their sheath	Pain on the thumb side of the wrist, worse with gripping and twisting
Lateral epicondylitis (tennis elbow)	Overuse of forearm tendons at the outer elbow	Outer elbow pain, weak grip, worse with gripping or typing
Trigger finger	A finger tendon catches in its tunnel	Catching or locking of a finger, often worse in the morning

The sources behind these rows: the American Academy of Orthopaedic Surgeons describes carpal tunnel, De Quervain's, tennis elbow and trigger finger, and the NHS covers tendonitis, where it names RSI as a cause.

Typing is not always the culprit. MedlinePlus says researchers are not sure whether long-term typing or computer use leads to carpal tunnel syndrome, and Germany's IQWiG rates the influence of computer work as fairly small. The AAOS links tennis elbow to repetitive gripping or wrist extension, and the NHS lists typing and mouse use among causes of tennis elbow.

A large overview of reviews reached a similar view:

"Computer use is associated with pain complaints, but it is still not very clear if this association is causal." — Andersen, Fallentin, Thomsen and Mikkelsen, occupational-health researchers, Risk factors for neck and upper extremity disorders among computers users and the effect of interventions: an overview of systematic reviews, PLOS ONE, May 2011

What causes RSI at computer work?

CCOHS lists the main workplace risk factors, which usually act together:

• fixed or awkward body positions
• continual repetition of the same movements
• force concentrated on the hand or wrist
• a work pace that leaves too little recovery time
• heat, cold or vibration
• stress and muscle tension

At a desk, that often means long stretches of typing and mousing without a break, a wrist bent upward, shoulders raised, or a deadline that keeps you going past the point of ache. Other risks have nothing to do with work. The AAOS lists being older, heredity, pregnancy, diabetes, rheumatoid arthritis and thyroid problems as risks for carpal tunnel. If your job and your hobbies use the same muscles, add them together.

What helps with RSI?

Because RSI has many causes, the best plan has steps: get the right diagnosis, lower the load on your hands, then use treatment that fits. The full five-step guide covers this in order.

The NHS gives these first moves: keep active but begin with less and build up gradually, consider paracetamol or anti-inflammatory painkillers such as ibuprofen (follow the leaflet or ask a pharmacist), and apply a cold pack wrapped in a towel for up to 20 minutes every 2 to 3 hours. It warns against resting the area for more than a few days, because that can cause weakness and stiffness. It also suggests talking to your employer about how you work. If symptoms persist, physiotherapy or occupational therapy may help.

Reducing the load can include your desk, your keyboard and mouse, and how much you type. See ergonomic desk setup and typing breaks and pacing. Treatment options, with evidence strength, are on the pages for exercises and medical treatments. The NHS says RSI often gets better on its own, but how long it takes depends on the cause.

This paper covered work-related arm pain in general, not computer work specifically:

"Ergonomic modifications can help to control symptoms, but optimal health may require collaborative management incorporating psychosocial and psychological elements of illness." — Moradi, Ebrahimzadeh and Ring, hand surgeons, Nonspecific arm pain, Archives of Bone and Joint Surgery, December 2013

When should I see a doctor?

See a doctor if symptoms are not going away or are getting worse. The NHS also notes you can self-refer to community musculoskeletal (MSK) services in many parts of the UK. Get checked sooner if you have numbness or tingling, especially at night, a weak grip or dropping things, or wasting of the thumb muscle, which the AAOS links to surgery to prevent permanent nerve damage. Pain after an injury, or sudden severe pain with a pop or snap, needs prompt care; the NHS (UK) advises contacting NHS 111 if you have severe pain or think a tendon has ruptured. Elsewhere, use your local urgent care or emergency number.

Elbow pain that continues after two weeks of rest and self-care is also worth a visit, according to the NHS. Read when to see a doctor for which doctor or therapist to start with.

Where to go next

Start with the five-step hand pain guide. Then read when to see a doctor, which tests you may be offered and carpal tunnel vs tendonitis.