The most common cause of shoulder pain is a problem with the rotator cuff, the group of tendons that steadies the joint. When these tendons are irritated or pinched beneath the bony roof of the shoulder, the result is tendinitis or bursitis. Other causes include frozen shoulder, arthritis, joint instability, an injured acromioclavicular (AC) joint, and pain referred from the neck or chest. This guide explains how to tell them apart, which symptoms need prompt care, and what you can safely do at home.
TL;DR
- Rotator-cuff problems, including tendinitis, bursitis and tears, are the most frequent source of shoulder pain.
- Where it hurts, when it hurts and how it started point toward different causes: stiffness over months, pain with arm use, a sudden injury, or pain at rest.
- Sudden severe pain, an arm you cannot move, numbness, fever, or pain after an accident needs urgent medical care. Shoulder pain with chest symptoms is an emergency.
- Staying gently active, short cold or heat sessions and progressive strengthening are the usual first steps for most shoulder problems.
- Pain that has not improved after about two weeks deserves a review by a doctor or physiotherapist.
Table of Contents
- The most common causes of shoulder pain
- What your pain pattern can suggest
- Everyday factors that make shoulders hurt
- Red flags: when shoulder pain needs prompt care
- How to reduce shoulder inflammation and discomfort safely
- Exercises and habits that help prevent shoulder injuries
- Explore your shoulder with InjuryAtlas
- FAQ
- Sources
The most common causes of shoulder pain
The shoulder is the most mobile joint in the body, and that mobility depends on soft tissue (tendons, muscles, bursae and ligaments) rather than on a deep bony socket. That is also why it is easily irritated.
MedlinePlus says the most common cause of shoulder pain is rotator-cuff tendons becoming trapped beneath the bony area of the shoulder, which causes inflammation or damage. The Merck Manual agrees that rotator-cuff tendinopathy is the leading cause, and that the supraspinatus tendon, which runs over the top of the joint, is the one most often involved.
Beyond the rotator cuff, a clinical review groups the usual suspects into four families: rotator-cuff disorders, glenohumeral (ball-and-socket) joint disorders, AC joint problems and referred neck pain. The American Academy of Orthopaedic Surgeons adds that most shoulder problems fall into tendon inflammation or tears, instability, arthritis and fractures, with tumours, infection and nerve disorders being much less common.
MedlinePlus also lists sprains, strains, dislocations, separations, tendinitis, bursitis, rotator-cuff tears, frozen shoulder, fractures and arthritis as everyday shoulder problems.
Rotator-cuff tendinitis, bursitis and impingement
The rotator cuff is four small muscles whose tendons wrap the top of the upper arm bone. Between the tendons and the bone above them sits a fluid-filled cushion, the bursa. When the space narrows or the tendons are overloaded, both can become irritated. People usually describe an ache at the front or side of the shoulder, pain when lifting the arm overhead or reaching behind, and discomfort lying on that side at night.
This pattern is often called shoulder impingement. Our guide to shoulder impingement causes and treatment walks through the structures involved, and the impingement recovery timeline sets out what progress usually looks like.
Rotator-cuff tears
A tear can follow a fall or a sudden heavy lift, or it can develop slowly from wear. Weakness lifting the arm is the feature that most separates a tear from simple irritation. Because the two can feel alike early on, we have written a side-by-side comparison: rotator cuff tear vs. shoulder impingement. You can also read about rotator-cuff tear causes and treatment.
Frozen shoulder and arthritis
Both tend to produce pain and stiffness that build over months or years rather than days. Frozen shoulder limits movement in every direction, including when someone else tries to move your arm. Arthritis often adds a grinding feeling and morning stiffness. The NHS links long-standing pain and stiffness with frozen shoulder or arthritis.
Instability and dislocation
A shoulder that feels loose, clicks, locks, or gives way, sometimes with tingling or a weak arm, may be unstable. This can follow a dislocation or occur in people with hypermobile joints. A dislocated shoulder is a medical emergency that needs to be put back in place by a clinician. Afterwards, a structured rehab plan matters, and our shoulder dislocation recovery plan lays out the stages.
AC joint injury
The AC joint is where the collarbone meets the top of the shoulder blade. A fall onto the point of the shoulder can sprain or separate it, causing pain and tenderness right on top of the shoulder. The NHS notes that pain on top of the shoulder suggests an AC joint injury.
Pain that starts in the neck or chest
Not all shoulder pain comes from the shoulder. MedlinePlus explains that neck or lung disorders can cause referred shoulder pain, which is usually felt at rest and does not get worse when you move the shoulder. A 2022 clinical review adds that sharp, shooting pain along the arm with hand numbness and a painless, full range of motion points toward the cervical spine rather than a primary shoulder disorder. A pinched nerve in the neck is a good example.
What your pain pattern can suggest
This table summarizes the patterns described in the NHS symptom guide. It is a starting point for a conversation with a clinician, not a diagnosis.
| What you notice | What it may suggest |
|---|---|
| Pain and stiffness building over months or years | Frozen shoulder or arthritis |
| Pain worse when you use the arm | Tendinitis, bursitis or impingement |
| Tingling, numbness, weakness, clicking or locking | Shoulder instability |
| Sudden severe pain and you cannot move the arm | Dislocation, fracture or tendon rupture |
| Pain on top of the shoulder | AC joint injury |
| Aching at rest, not changed by shoulder movement | Referred pain from the neck or chest |
Cleveland Clinic suggests noting what triggered the pain, how quickly it began, exactly where it hurts, whether it spreads, and what makes it better or worse. It also recommends tracking weakness, mobility, sleep disturbance, swelling, bruising, warmth and tenderness. Writing these down before an appointment makes the assessment faster and more accurate.
If you want to see where each structure sits, the shoulder anatomy encyclopedia lets you explore the joint and match your pain location to the tissues underneath.
Everyday factors that make shoulders hurt
A specific injury is not always needed. MedlinePlus lists arthritis, bone spurs, muscle imbalance, nearby tendon injury, nerve injury, and poor posture or shoulder mechanics among the contributors. The clinical review mentioned earlier also notes that repetitive arm work and prolonged arm elevation are relevant occupational factors.
In practice that often means:
- Long hours at a keyboard with the shoulders rounded forward.
- Painting, overhead lifting or other work with the hands above shoulder height.
- Throwing, swimming or racquet sports when volume rises faster than conditioning.
- A sudden return to weights or sport after a long break.
AAOS advises that shoulder pain can be avoided by not overusing the shoulder suddenly or doing activities beyond your usual conditioning. If you sit most of the day, our guide to shoulder injury prevention for desk work covers setup and movement breaks.
Red flags: when shoulder pain needs prompt care
Most shoulder pain is not dangerous, but a few signs should not wait. The NHS advises urgent care for sudden or severe pain, being unable to move the arm, deformity or major swelling, persistent pins and needles, numbness, abnormal hot or cold temperature, pain after an accident, severe pain in both shoulders, or a feverish illness. It suggests a routine medical review if the pain is getting worse, has not improved after two weeks, or movement is very difficult.
Two situations deserve particular attention:
- Shoulder or left-arm pain with chest symptoms. Cleveland Clinic states that referred pain with a possible heart attack, pulmonary embolism or aortic dissection is an emergency. If shoulder or arm pain comes with chest pressure, shortness of breath, sweating or faintness, call 911 rather than waiting to see whether it passes. This applies to women and men alike.
- Sudden weakness or numbness. The same source says sudden tingling, numbness, weakness or paralysis, or a sudden inability to use the arm normally, needs immediate medical attention.
Clinicians also look for signs of infection or cancer. A primary-care review lists fever, weight loss, a history of cancer, local warmth and shoulder swelling as red flags needing same-day referral. A 2021 referral guideline calls for same-day emergency referral for a suspected infected joint or a dislocation that has not been reduced, and it treats systemic inflammatory disease or polymyalgia rheumatica as reasons for prompt rheumatology referral.
Our perspective
We built InjuryAtlas around one idea: you cannot manage a shoulder problem well if you do not know which structure is involved. "Shoulder pain" is a symptom, not a diagnosis. Impingement, a rotator-cuff tear, an irritated AC joint and a pinched neck nerve can all hurt in roughly the same place, yet each calls for a different plan.
That is why our guides start from the anatomy and connect each symptom, injury and exercise to the specific structure behind it. You can begin from where it hurts, from a named injury or from a training goal, and follow linked pages from there. We write in plain language and grade the evidence, so you can see what is well supported and what is not.
We also want you to use that understanding alongside a clinician, not instead of one. Arriving at an appointment able to describe your pain precisely, and knowing which structures are likely involved, makes the visit more productive for you and for your physiotherapist or doctor.
Josh
How to reduce shoulder inflammation and discomfort safely
For most mechanical shoulder pain, early self-care is simple. The NHS advice is to stay active and gently move the shoulder, avoid things that seem to make it worse, and try wrapped cold or heat packs for up to 20 minutes. Specifically, it describes a wrapped bag of frozen peas up to three times a day, or a wrapped hot-water bottle two to three times a day. Never put ice or heat directly on the skin.
It adds that over-the-counter pain relief such as paracetamol or ibuprofen may help you keep moving. Check with a pharmacist or doctor first if you have stomach, kidney or heart conditions, take blood thinners, or are pregnant, since anti-inflammatory medicines are not suitable for everyone. AAOS likewise recommends activity modification, rest, physical therapy for strength and flexibility, and anti-inflammatory medicines directed by a clinician, and notes that most patients respond to these simple measures.
A few practical points follow from that advice:
- Do not immobilize the shoulder completely. Prolonged rest tends to stiffen it. Keep moving within a comfortable range.
- Change the trigger, not just the symptom. If overhead reaching hurts, bring shelves and tools down for a while.
- Support the arm. Resting the forearm on a pillow or armrest takes load off the joint.
- Avoid heavy gym equipment and strenuous exercises you design yourself while the shoulder is sore, as the NHS cautions.
- Give it time, with a plan. A 2021 referral guideline describes an initial six-week physiotherapy course, with a further six weeks justified when improvement is occurring.
If impingement is the likely cause, our shoulder impingement recovery plan and impingement rehab guide set out exercises in stages. For an overview of all shoulder conditions, see our shoulder recovery hub.
Exercises and habits that help prevent shoulder injuries
Strength and flexibility protect the joint. AAOS explains that strength supports joint stability while flexibility helps restore motion and prevent injury. Its conditioning program targets the deltoid, trapezius, rhomboids, teres muscles, the rotator-cuff muscles (supraspinatus, infraspinatus and subscapularis), biceps and triceps.
The same program suggests a 5-to-10-minute low-impact warm-up before stretching and strengthening the shoulder and upper-back muscles. After recovery, two to three sessions per week can maintain strength and range of motion. It also says not to exercise through pain, and to ask a doctor or physical therapist for guidance.
The approach is consistent across countries. France's national health authority recommends physiotherapy that includes progressive rotator-cuff and shoulder-complex strengthening, range-of-motion work, posture correction, neuromuscular training and a taught self-rehabilitation programme, with improvement expected over six weeks to three months. It treats active, progressive rehabilitation as the core of care, with regular reassessment, rather than passive treatments alone. The NHS similarly suggests trying exercises for six to eight weeks and improving your posture.
A sensible weekly routine for a healthy shoulder looks like this:
- A short warm-up of easy arm circles and gentle movement before activity.
- Two to three strengthening sessions covering the rotator cuff, upper back and shoulder blade muscles.
- Regular posture changes during desk work, not one perfect position held for hours.
- Gradual increases in training volume, especially for overhead sport and lifting.
You can browse demonstrations by body region and difficulty in our exercise library.
Explore your shoulder with InjuryAtlas
If you are trying to work out what is behind your pain, InjuryAtlas lets you explore the shoulder in interactive 3D, pinpoint where it hurts, and follow connected guides from symptom to structure to recovery and exercise. With more than 79 anatomy guides and encyclopedia entries covering the upper body and knee, you can read about an injury in plain language and see which tissues are involved.
Start on the InjuryAtlas home page and choose the shoulder, or go straight to the shoulder anatomy encyclopedia.
FAQ
What is the most common reason for shoulder pain?
Rotator-cuff problems are the most common cause. MedlinePlus describes tendons becoming pinched beneath the bony part of the shoulder, leading to tendinitis or bursitis. The Merck Manual identifies the supraspinatus tendon as the one most often involved.
Why does my shoulder hurt when I lift my arm or lie on it at night?
Pain that worsens with arm use usually points to tendinitis, bursitis or impingement, where irritated tissues are squeezed as the arm rises. Lying on the sore side can compress them further. A physiotherapist can confirm which structure is involved and guide your exercises.
Can shoulder pain be a sign of a heart problem?
Yes, sometimes. Pain referred from the heart, lungs or major blood vessels is usually felt at rest and does not change with shoulder movement. If left shoulder or arm pain comes with chest discomfort, breathlessness, sweating or faintness, call 911 immediately.
How long should I wait before seeing a doctor?
Go urgently for sudden severe pain, an arm you cannot move, numbness, fever, or pain after an accident. For milder pain, the NHS suggests a medical review if it is getting worse, has not improved after two weeks, or makes movement very difficult.
What helps shoulder inflammation settle?
Stay gently active, avoid the movements that provoke pain, and use wrapped cold or heat packs for up to 20 minutes at a time. Progressive physiotherapy exercises are the main treatment for most causes. Ask a pharmacist or doctor before using anti-inflammatory medicines.
Sources
- Shoulder pain: MedlinePlus Medical Encyclopedia
- Shoulder Injuries and Disorders: MedlinePlus
- Evaluation of the Shoulder: Merck Manual Professional Edition
- The painful shoulder: an update on assessment and treatment (PMC)
- Shoulder Pain and Common Shoulder Problems: OrthoInfo (AAOS)
- Shoulder pain: NHS
- An algorithmic approach to shoulder pathology (PMC)
- Shoulder Pain Causes and Treatment: Cleveland Clinic
- Assessment and management of shoulder pain at primary care (PMC)
- Shoulder Pain Diagnosis, Treatment and Referral Guidelines (PMC)
- Rotator Cuff and Shoulder Conditioning Program: OrthoInfo (AAOS)
- Diagnostic management of non-traumatic shoulder pain in adults: Haute Autorité de Santé