Where it hurts is a clue, not a diagnosisEmerging evidence
A study of 94 people at an English hospital mapped where shoulder pain was felt against the final diagnosis. Rotator cuff pain was mainly sharp, around the front of the shoulder, and ran down the arm; rotator cuff tears followed the same pattern; and arthritis of the shoulder joint affected the whole arm. A clinical review says most shoulder pain is diagnosed from the story and an examination. So this guide says a spot points to a cause rather than proving it, and an examination decides.
Sources 1, 2
Most upper arm pain is the shoulderStrong evidence
Rotator cuff problems are the most common cause of shoulder pain in general practice, usually between 35 and 75, a clinical review says. NHS inform calls subacromial pain syndrome, pain from the rotator cuff tendons and the fluid sac above them, the most common reason for shoulder pain, and its main symptom is pain in the upper arm, with lifting the arm above shoulder level and reaching behind your back, for example putting on a jacket.
The American Academy of Orthopaedic Surgeons (AAOS) describes rotator cuff pain spreading from the front of the shoulder to the side of the arm, often worst at night, and says people who lift repeatedly or work overhead are more at risk. NHS inform adds that shoulder problems can come from the neck even when your neck doesn't hurt.
Sources 2, 3, 4, 1, 5
Rotator cuff tearsStrong evidence
The AAOS says rotator cuff tears often cause pain at rest and at night, and weakness lifting or turning the arm. A tear from a fall causes intense pain, a snapping feeling and immediate weakness in the upper arm; some tears cause no pain at all. Treatment without surgery relieves pain and improves function in about 80% to 85% of people.
Source 6
The bicepsStrong evidence
The long head of the biceps runs over the front of the shoulder. When it tears, usually through wear (age, overuse, smoking and steroid medicines raise the risk), the AAOS describes sudden, sharp pain in the upper arm, sometimes a pop, bruising down towards the elbow and a bulge low in the upper arm, often called a Popeye muscle. Most people need only simple treatment, and the pain usually goes away over time.
A tear of the biceps tendon at the elbow is uncommon, 3 to 5 people per 100,000 a year, mostly men over 30, usually during a heavy lift: a pop at the elbow, bruising at the elbow and forearm, weakness bending the elbow and turning the palm up, a bulge in the upper arm and a gap at the front of the elbow.
Sources 7, 8
The triceps
Pain at the back of the upper arm just above the elbow, worse straightening against resistance, points to the triceps tendon, which our triceps guide covers. A full tear is rare, usually from a fall onto an outstretched hand or a heavy press, and needs the same-day care in the warning signs.
Stiff in every direction: frozen shoulderStrong evidence
Frozen shoulder most often affects people aged 40 to 60, more often women and people with diabetes; the AAOS says its pain is usually over the outer shoulder and sometimes the upper arm, and the NHS says it can be worse at night and take months or years to get better. What marks it out is stiffness in every direction, whoever moves the arm, while rotator cuff pain usually lets someone else lift the arm fully.
Sources 9, 10, 2
From the neck: a pinched nerveStrong evidence
The AAOS says pain from a trapped nerve in the neck (cervical radiculopathy) usually starts at the neck and travels down the arm, burning or sharp, with tingling, numbness or weakness, and some neck movements make it worse. In a Minnesota population it affected 83 people per 100,000 a year, most often at 50 to 54; wear of the spine caused most of it, a disc bulge about a fifth, and an injury or effort came first in only about 15%.
NHS inform says numbness, pins and needles or weakness in one or both arms that is getting worse needs urgent help.
Sources 11, 12, 13
After a fall: a breakStrong evidence
After a fall or an injury, a broken arm is painful, swollen and bruised, hard to move, and may change shape or colour or feel numb, the NHS says. A break at the top of the arm bone causes swelling, bruising around the top of the arm and an arm you can't move, and the AAOS says most can be treated without surgery if the pieces haven't moved far.
In a review of 4,517 breaks of the shaft of the arm bone, 11.8% came with a radial nerve palsy, a wrist that won't lift, and 88.1% of those recovered, most without surgery.
Sources 14, 15, 16
Jabs, new workouts and statinsEmerging evidence
A sore arm is a common side effect of a vaccine: the NHS says flu vaccine side effects are mild and get better within 1 to 2 days, and COVID-19 vaccine side effects within a week. Rarely, a shoulder becomes painful and stiff for longer after a jab given too high in the shoulder, described in a series of 13 people.
Soreness a day or two after unfamiliar exercise, especially lowering work, is delayed onset muscle soreness. Much more rarely, very hard exercise breaks down muscle (exertional rhabdomyolysis), causing pain, weakness and swelling in the worked muscles, about 30 cases per 100,000 patient-years in one estimate, and the NHS asks for any blood in the pee to be checked. Statins can cause muscle aches too.
Sources 17, 18, 19, 20, 21, 22, 23
The heart, polymyalgia and other causesStrong evidence
The NHS says call 999 for arm pain that has come on suddenly with pressure, heaviness or squeezing across your chest; angina can cause pain in the chest, neck, shoulders, jaw or arms, often brought on by exercise and easing with rest; and the British Heart Foundation says women's heart attack pain can spread to either arm, the neck, jaw, upper back or stomach.
Polymyalgia rheumatica causes pain and stiffness around the shoulders, neck and hips, with morning stiffness lasting more than 45 minutes, mostly in people over 65 and very rarely under 50 (an NHS page past its review date). Bone pain that is constant or worse at night, or a lump, needs a GP.
Sources 24, 25, 26, 27, 28, 29
When a scan or test helpsStrong evidence
Most upper arm pain is diagnosed from the story and an examination; blood tests and X-rays are for warning signs such as feeling unwell, a history of cancer, a lump or tender bone. An ultrasound or magnetic resonance imaging (MRI) scan shows the rotator cuff when a tear would change the plan, such as sudden weakness after an injury, and frozen shoulder doesn't need one. A suspected break needs an X-ray.
A torn long head of the biceps is usually obvious from the bulge, and an MRI shows partial and complete tears; a tear at the elbow is checked by feeling for the gap, with a scan to confirm. For a trapped nerve, X-rays, an MRI and nerve tests help when it doesn't settle or the diagnosis is unclear, though the AAOS says nearly half of middle-aged and older people have worn discs and pinched nerves that cause no symptoms. Suspected heart pain needs an electrocardiogram (ECG) and blood tests in hospital.
Sources 2, 6, 9, 14, 7, 8, 11, 25
How it usually goesEmerging evidence
The NHS says shoulder pain usually needs 2 weeks of looking after it yourself before it starts to ease, and can take 6 months or longer to recover (a page past its review date); NHS inform expects new shoulder problems to begin to settle within 6 weeks. Treatment without surgery relieves about 80% to 85% of rotator cuff tears, and after a torn long head of the biceps the pain usually goes away. Frozen shoulder passes through freezing (6 weeks to 9 months), frozen (4 to 6 months) and thawing (6 months to 2 years) stages.
Arm pain from a trapped nerve eased by about 3 points a week on a 100-point scale even without treatment in a Dutch trial, and 90% of a Minnesota population were free of symptoms or only mildly limited when followed up, though it came back in about a third. A broken arm usually takes 6 to 12 weeks to heal, and most nerve palsies with a break recover. A sore arm after a vaccine settles within days. No one can promise a date.
Sources 30, 5, 6, 7, 9, 31, 12, 14, 16, 17, 18
