Tendinosis is where a tendon’s collagen degenerates in response to overuse. Tendonitis, however, is when a tendon becomes inflamed. The umbrella term for these conditions is tendinopathy.

Tendinosis and tendonitis are often confused with one another. For example, people frequently call “tennis elbow” tendonitis when it is, in fact, an example of tendinosis.

This article looks at the key differences between tendinosis and tendonitis. It explains symptoms, causes, and treatment for each condition.

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Tendinosis and tendonitis are two types of issues of the tendons that fall under the category of tendinopathy.

These two conditions are easily confused, as they share some similarities. However, they typically result from different causes and have differing symptoms.

Tendinosis is generally due to degeneration of the tendon due to overuse, injury, or improper healing. It does not typically involve inflammation. Tendinosis usually takes longer to heal than tendonitis.

Tendonitis is the inflammation of the tendon following an injury.

The result of deterioration of the tendon’s collagen.The result of inflammation of a tendon.
Occurs through repetitive strain on the tendon.Occurs because of micro-tears that happen when the tendon is overloaded with overuse, heavy, or sudden force.
Causes disorganization in the fibers and a thick, scarred appearance.Usually heals in 2–3 weeks.
Usually heals in 3–6 months.

Learn more about tendinopathy.

Though symptoms for both conditions are similar, there are a few notable differences.

Symptoms of tendinosis

The symptoms of tendinosis include:

  • stiffness in the joint
  • burning pain and swelling around the tendon
  • restricted movement of the joint
  • pain that worsens during and after activity
  • pain that has been persistent for several months

Symptoms of tendonitis

The symptoms of tendonitis include:

  • pain in the tendon that worsens with movement
  • difficulty moving the joint
  • swelling and inflammation that may include heat, redness, or discoloration
  • a grating or crackling sensation when moving the joint
Pain that is affected by movementxx
Restricted or difficult movement of the jointxx
Burning painx
Stiffness of the jointx
Grating or crackling sensation in the jointx
Inflammation that can include redness or discoloration and heatx
Pain that persists for several monthsx

Tendon injuries are commonplace among people of all ages, though they are more common in adults than children. People can strain tendons from repetitive use, such as:

  • sports
  • types of work
  • playing an instrument
  • aging

Common causes of tendinosis

Common causes of tendinosis include:

  • Trauma: Physical trauma from sports activities or a fall can cause disorganized collagen fibers and tears.
  • Overuse: Repetitive strain on a tendon can result in tendinosis. This can be from something as simple as repeatedly clicking a mouse for work.
  • Osteoarthritis: Over time, the cartilage and bone wear away in certain areas for people with osteoarthritis. This might make the tendons around that area more prone to injury.
  • Aging: As people age, their bodies produce less collagen, which may slow tendon healing. Healing failure is one of the main causes of tendinosis.
  • Fluoroquinolones: This is a type of antibiotic that treats bacterial infections that can cause damage to tendons.
  • Obesity and diabetes: The risk of tendinopathy is higher for people who have type 2 diabetes or overweight or obesity.

Common causes of tendonitis

The cause of tendonitis is not always known. However, some causes may include:

  • Inflammation: Tendonitis, unlike tendinosis, is the result of a swollen and inflamed tendon that does not have microscopic damage.
  • Overuse: Repetitive motions can cause tendonitis. Many occupations involve repetitive motions, such as construction workers, musicians, gardeners, and carpenters.
  • Strain: Activities like weightlifting put tendons under strain, especially if a person does not warm up properly.
  • Injury: Sharp, sudden movements can result in tendon injury and tendonitis. Jumping, throwing, and running are common examples.

Tendinosis may be considered the more serious of the two conditions because it is degenerative. Tendinosis takes longer to recover from than tendonitis and can be chronic. Untreated tendinosis can also lead to ruptured tendons.

However, which is more painful will depend on the person experiencing it, the severity, and the location of the condition.

Both tendonitis and tendinosis commonly occur in the following tendons:

  • Achilles: This is the tendon in the back of the heel.
  • Patellar: This is the tendon that connects the kneecap to the shinbone.
  • Gluteal: These are the tendons on the outside of the hips.
  • Wrist extensor: The tendon on the outside of the elbow. Tendinosis in this area is commonly referred to as “tennis elbow”.
  • Rotator cuff: The tendon that supports shoulder rotation.

Tendinosis can often be misdiagnosed as tendinitis.

Some anti-inflammatory treatments for tendonitis – such as corticosteroid injections – can exacerbate tendinosis symptoms and accelerate the rate of the tendon’s deterioration.

A healthcare professional can often distinguish between tendonitis and tendinosis by scanning the affected area using an ultrasound or MRI. This is one reason it is important for people to see a healthcare professional to receive the most accurate diagnosis possible for their situation.

Tendonitis treatment

Treatment for tendonitis may include:

  • Icing the area: Using ice for up to 20 minutes every 2–3 hours can help to bring down inflammation in tendonitis and reduce pain.
  • Rest: A person should try to avoid moving the tendon for around 2–3 days.
  • Support: Wrap the affected area in an elastic bandage or use a soft brace to support the area. Make sure the bandage is not too tight.
  • Corticosteroid injections: Corticosteroid injections can reduce inflammation, short-term pain, and swelling. However, they may impair collagen production, so may not be suitable for tendinosis cases.

Tendinopathy treatments

Treatments for tendon injuries, including tendinosis, may include:

  • Stretching: Stretching is important to reduce the chance of injury when it comes to any form of exercise. It is also important for injury, as it increases the range of motion of the tendon and promotes circulation.
  • Rest: Avoiding repetitive movements or taking regular breaks when performing repetitive activities can help speed up the healing process.
  • Bracing or taping: Taping or bracing helps stabilize the injured area and decrease potentially harmful movement.
  • Massage: Massaging the affected area can help promote circulation and healing.
  • Exercise: Eccentric exercises help provide mechanical stimulus to the parts of the tendon that can help deposit new collagen and remove disorganized collagen. Building the muscles around tendons can also reduce daily strain. For example, studies report the benefits of backward walking on an incline for knee pain.
  • Supplements: Supplementing with vitamin C, glucosamine, chondroitin sulfate, L-arginine, collagen peptides, and turmeric may help repair damaged tendons or prevent them from further deterioration.
  • Physical therapy: Physical therapy techniques are popular treatments for tendinopathy. A physical therapist can give advice on the best exercises for an individual to do to help heal the affected area.
  • Surgery: Operating on the area to remove damaged tissue can help allow the tendon to heal. However, this is only an option when other treatments have not been effective.

An individual should speak with a healthcare professional about the most effective ways of treating an injured tendon.

People should contact a healthcare professional if they are experiencing any of the following in the affected area:

  • pain, burning, or swelling
  • the area is hot to the touch
  • muscle weakness
  • fever, chills, or sweats
  • reduced range of motion
  • crackling or grating sensation in the joint

Tendonitis and tendinosis are common forms of tendinopathy, the result of damage to the tendons.

Tendinosis is a degenerative disorder resulting from collagen breakdown in the tendons. Tendonitis is inflammation of the tendon as the result of overuse or strain.

Both conditions are treatable with time, rest, physical therapy, and help from a healthcare professional. If an individual is experiencing swelling, reduced motion in a joint, pain that worsens with use, or muscle weakness, they should contact their healthcare professional.