What does rotator cuff tendinitis feel like?

The pain sits on the outside of the upper arm, a hand width below the top of the shoulder. It bites when you reach up to a shelf, put on a coat or throw a bag into the back seat. Night is worse. Rolling onto that shoulder wakes you up, and many people start sleeping in a recliner.

The arm still lifts. That is the key difference from a frozen shoulder or arthritis, where the joint itself loses motion. With tendinitis, the motion is there, it just hurts in the middle of the arc. If the arm suddenly cannot lift at all after a fall or a hard pull, that points to a tear, and it needs a scan soon.

Pain that runs past the elbow, with tingling into the hand, is a different story. That is usually a nerve in the neck. Our cervical radiculopathy page explains how we tell them apart.

Why does a rotator cuff tendon wear out?

The word tendinitis suggests a fire. In a tendon that has hurt for months, there is less fire and more fraying. The collagen fibers lose their neat rows, small blood vessels grow in where they should not, and the tendon gets thick and weak at the same time. Doctors now call that tendinopathy.

Three things drive it. The first is the work. Metro East jobs load the shoulder hard: stocking shelves on a warehouse shift in Edwardsville, overhead welding at a mill, turning wrenches on a flight line, lifting patients on a hospital floor. The second is age. Cuff tendons lose blood supply after forty. The third is blood sugar. High sugar bonds to collagen and makes the tendon stiff and brittle, which is why cuff problems are so common in people with diabetes. We check that bloodwork at the first visit, for reasons laid out in metabolic health and pain.

Why did my cortisone shot for the shoulder stop working?

A steroid shot into the space above the tendon quiets pain fast. It does not rebuild the fibers. Repeated steroid near a tendon can weaken it further. So the first shot works for months, the next one for weeks. A 2026 analysis of ten randomized trials with 591 patients compared PRP with steroid for this exact problem. At six weeks and three months the two were about even. At six months PRP was ahead on pain and shoulder function, and it caused fewer side effects.

How does PRP treat rotator cuff tendinitis?

We draw a small amount of your blood, spin it, and concentrate the platelets. Platelets carry the signals that tell a damaged tendon to lay down new collagen. Using ultrasound, we place that concentrate into the worn part of the tendon itself, not just near it. You can watch the needle on the screen with us.

The strongest single trial is worth knowing. In a double-blind study of 100 adults under 50 with a worn supraspinatus tendon, those who got PRP had less pain, better shoulder scores and better sleep at one year than those who got steroid. Fewer of them needed another injection.

Why do dose and rehab decide the result?

PRP made with a quick spin can hold barely more platelets than plain blood. We prepare a concentrated dose and confirm placement with ultrasound, because a tendon only responds to the signal that reaches it.

Then the tendon has to be loaded. A new collagen fiber lines up along the force it feels. Without the right exercise, it lays down in a tangle. Your plan starts with gentle loading of the cuff and the muscles that hold the shoulder blade, then builds week by week toward the reach your job or your sport demands. Sleep and blood sugar are part of the plan, because both set how fast a tendon can rebuild.

What happens on the day of the injection?

You are awake. We numb the skin with local anesthetic. There is no sedation, so most people drive themselves home across the river. The shoulder is sore for about 48 hours. Whether you need a second injection depends on how the first one did, and we decide that together at follow-up.

Hurt it on the job in Illinois? Illinois generally lets the injured worker choose the treating doctor. Our injured at work page explains how that works.

Will shaving the bone above the tendon fix it?

For years the standard operation for a painful cuff was a subacromial decompression: shave the underside of the bone above the tendon so it stops rubbing. A Finnish trial tested that idea against placebo surgery. 210 patients with shoulder impingement were assigned to the real decompression, to a diagnostic arthroscopy where the surgeon looked inside and did nothing else, or to exercise. At two years, the real operation was no better than the look-and-close operation on pain at rest or with arm use.

The shoulder improved in both surgical groups, which tells you how much of the benefit came from time, rest and rehab rather than the bone shaving. That result is a reason to build the tendon first and save the operating room for the tears that need it.

Dr. Padda told patients with prediabetes for years that their A1C was not too bad. He was wrong, and the shoulder is one of the places that mistake shows up first. An A1C in the high fives means sugar has been coating proteins for months, cuff collagen included. So the plan for a stubborn cuff includes the bloodwork, a food change that brings that number down, and a walk after the largest meal, which pulls glucose into muscle instead of leaving it in the blood to stiffen the tendon.

When does a rotator cuff need surgery?

Most cuffs never need it. Conservative care matches surgery for partial-thickness cuff tears, which are about twice as common as full-thickness ones. Eubank and colleagues, in a 2024 review of 28 level-1 trials, started from the numbers: “Studies have shown partial-thickness rotator cuff tear (PTRCT) prevalence to be twice that of full-thickness tears.” A 2026 review of 16 studies by Trygonis and colleagues reached the treatment side: “Conservative treatment, primarily physiotherapy-based, demonstrated comparable outcomes to surgery in partial-thickness tears or low-demand individuals.” So a partial tear here gets an ultrasound-guided injection, PRP into the tendon, a loading program and the metabolic work above, and we work to avoid surgery on it. The exceptions are a full-thickness tear in a younger, active person, a sudden tear after an injury with real weakness, or a tear that keeps growing on repeat scans. We tell you when that is the case and coordinate the referral.

Which shoulder warnings send you to the ER instead?

• Left shoulder or jaw pain with chest pressure, shortness of breath, sweating or nausea. That can be the heart. Call 911.
• Sudden arm weakness with a drooping face or slurred speech. Call 911.
• A shoulder that looks out of place or cannot move at all after a fall.
• Fever with a hot, swollen shoulder.

More on these in when it is an emergency.

Frequently asked questions

Do I need a referral for rotator cuff tendinitis?

No. You can schedule the shoulder visit yourself. Some insurance plans, mostly HMOs, ask for a referral from your primary doctor before they pay, so check yours or ask us to check. The first-visit guide for Illinois patients covers what to bring.

Is rotator cuff tendinitis the same as a rotator cuff tear?

No. Tendinitis is a worn, painful tendon that is still in one piece. A tear is a gap in the tendon. Many shoulders have some of both, and ultrasound shows which one is driving the pain.

How long after PRP will my shoulder feel better?

Most people notice a change over six to twelve weeks, as the tendon rebuilds. That is slower than a steroid shot, and it tends to last longer.

Can I keep working after a shoulder PRP injection?

Most people go back to light duty within a few days. Heavy overhead work waits until the rehab says the tendon is ready.

Does insurance cover PRP for the rotator cuff?

Most plans do not. That is a budgeting choice about what a plan funds, not a judgment on the treatment. HSA and FSA funds can generally be used.

Can I sleep on my bad shoulder?

Try not to for now. Sleep on your back or the other side with a pillow hugged against your chest. That keeps the sore tendon from being pinched all night.

Should I stop lifting weights with rotator cuff tendinitis?

Do not stop moving the arm. Stop the lifts that cause sharp pain, and keep the ones you can do comfortably. The right load helps the tendon heal.

Related reading

• Cervical radiculopathy
• Tennis elbow
• Trigger point injections
• Image-guided joint injections
• Injured at work
• Metabolic health and pain
• PRP, bone marrow concentrate and microfragmented fat, compared