Symptoms of Inclusion Body Myositis
Inclusion body myositis (IBM) usually causes slowly progressive muscle weakness that develops over months to years. Common early symptoms include difficulty climbing stairs or rising from a chair, frequent tripping or falls, and weakening grip or hand function. Some people also develop swallowing difficulty (dysphagia). Because symptoms often begin subtly and overlap with other conditions, IBM is frequently not recognized right away.
IBM can eventually affect many skeletal muscles throughout the body, but it often affects certain muscles first, which creates recognizable patterns of early symptoms. These symptoms are primarily due to loss of strength rather than poor coordination or endurance. Someone may be able to walk long distances but be unable to step up onto a kitchen chair to change a lightbulb. Another may be able to play the piano but be unable to move heavy furniture because their grip is too weak to hold on.
Asymmetry is a common feature of inclusion body myositis. This means the weakness is often uneven, with one side of the body weaker than the other. In many people, the dominant side remains somewhat stronger, so a right-handed person may notice more weakness on the left side than on the right.
General symptoms of IBM can include fatigue and an overall sense of reduced strength. Daily tasks may feel more tiring, even before weakness in a specific muscle group becomes obvious. Some people first suspect something is wrong when they lift weights consistently but do not get stronger the way they used to.
Leg Symptoms
Early leg symptoms are often caused by weakness of the quadriceps, the powerful muscle on the front of the thighs that stabilizes the knee and straightens the leg.
Getting Up and Climbing
Quadriceps weakness makes it hard to get up from low surfaces. People may complain of being unable to get out of a bathtub, get up from the ground while gardening, or stand after squatting to tie a shoe. It may be necessary to push off with the arms when standing from a low chair or toilet. The weakness also makes it hard to climb a ladder or stairs. Handrails become necessary, and it may be impossible to carry anything while climbing stairs.
Going Down, Sitting, and the “IBM Plop”
The quadriceps is also used to control descending motions, such as walking down inclines, stepping off a curb, or sitting down. People with IBM often experience the “IBM plop,” referring to their abrupt descent as they fall into a chair—sometimes hard—rather than slowly lowering themselves. Armrests are often used to slow the descent.
Leg Power and Speed
Because IBM reduces leg power, running and other quick movements may become difficult or impossible. Some people describe this more generally as heaviness in the legs or an inability to move quickly.
Falls
Many people first suspect something is wrong because of repeated falls. Sometimes someone will suddenly crumple to the ground when a knee gives out. Mild collisions or a step on uneven ground can lead to falls because the muscles are not strong enough to recover quickly and maintain balance. Weakness of the muscles that lift the front of the foot can also cause foot drop, making it easy to catch the toes and trip—for example, on a crack in a sidewalk or the edge of a rug.
Mobility Aids
Many people progress to using a cane, then a walker or rollator, and then a wheelchair, but the disease is variable, and some people continue to walk without assistance.
Hand Symptoms
Early hand symptoms in inclusion body myositis are usually caused by weakness of the muscles that bend the fingers, leading to a weak grip and reduced strength when grasping or squeezing. Common problems include difficulty opening jars, turning doorknobs, turning keys in locks, pulling on socks, pulling open a potato chip bag, or squeezing bicycle brakes, pruning shears, or gas pumps. People may start dropping objects, such as a glass of water. People may also have difficulty pressing down with one finger to use hair spray, insect repellent, spray cleaners, pump soap, or similar bottles and dispensers.
Hobbies and sports can also be affected. Some golfers notice that clubs begin to slip or even fly out of their hands. Weak grip may also cause problems in the gym, where heavy lifting or pull-ups can become impossible—not at first because of weakness in the arms or body, but because the hands are no longer strong enough to hold onto the bar.
As weakness worsens, people may begin to lose dexterity, making fine finger tasks more difficult. Buttoning a shirt, zipping a jacket, tying shoes, picking up a pill, using utensils, writing, typing, and playing a musical instrument may all become harder.
The small muscles within the hand are often less affected early on, allowing some people to pick up light objects by squeezing them between two straight fingers. The thumb is also often less affected early in the disease, so many people with inclusion body myositis learn to hold objects between the thumb and the palm even after they can no longer grip them normally with the fingers.
Swallowing Symptoms (Dysphagia)
Swallowing difficulty, known as dysphagia, eventually affects many people with inclusion body myositis, although it is usually less prominent than leg weakness or finger flexor weakness early in the disease. Many people do not mention swallowing problems unless they are specifically asked.
In some people, however, dysphagia is the first symptom and may remain the main problem for several years. ENT physicians and swallowing therapists should keep IBM in mind when evaluating patients with otherwise unexplained swallowing difficulty.
In IBM, dysphagia can range from mild to severe and may gradually worsen over time. Symptoms may include coughing or choking while eating or drinking, needing extra effort or repeated swallows, or feeling that food sticks in the throat. Sips of liquid may help food go down.
Eating difficulties can lead to poor nutrition, which accelerates muscle loss. Dysphagia is also important because it can increase the risk of aspiration (food or liquid going into the airway) and aspiration pneumonia.
Breathing Symptoms
Sleep Apnea and Sleep-Disordered Breathing
Sleep-disordered breathing, including sleep apnea, may be more common in inclusion body myositis than was once recognized, especially later in the disease. The cause is not fully understood. Weakness or dysfunction of the throat muscles may contribute in some people, particularly when swallowing is also affected. Symptoms may include loud snoring, pauses in breathing during sleep, morning headaches, unrefreshing sleep, or unusual daytime sleepiness. Treatment is available, so these symptoms should be discussed with a doctor.
Respiratory Failure
Daytime breathing symptoms are uncommon early in inclusion body myositis. They can develop later in the disease as the diaphragm and other breathing muscles become weaker.
Facial and Eye Symptoms
Inclusion body myositis can also affect the face, although facial weakness is usually mild. Weakness of the muscles around the eyes may make eyelid closure less forceful or incomplete, potentially exposing the eyes to the air. Some people develop dry, irritated, or painful eyes, especially during sleep, and may need artificial tears or bedtime lubricating ointment. In more severe cases, poor eyelid closure can irritate and damage the surface of the eye.
Trunk and Neck Symptoms
Symptoms related to the trunk and neck are rare. Camptocormia is a medical term referring to forward bending of the trunk, and applies to a few IBM patients who cannot hold their torso upright due to weak spine muscles. Similarly, it is possible to have head drop, with the chin resting on the chest due to weak neck muscles.
Pain
Pain can occur in inclusion body myositis, although it is not usually the main symptom. In the past, IBM was often described as a painless disease, but more recent patient-based research has shown that many people with IBM do experience pain. Researchers still do not fully understand the cause. In some cases, pain may not come directly from the muscle disease itself, but from the effects of weakness on the body over time. Weak muscles can change posture, gait, balance, and joint support, which may lead to back pain, joint pain, or other musculoskeletal discomfort. This is a reasonable explanation, but it has not yet been proven, and more research is needed.
Further reading: Open-access journal article on pain in myositis, including inclusion body myositis
How Symptoms Typically Progress
Inclusion body myositis does not affect everyone in the same way. Symptoms can start at different ages, the muscles most affected may differ from person to person, and the disease can progress more quickly in some people than in others. As a result, the overall degree of disability varies widely. Changes in function may seem to happen in steps rather than in a smooth, steady way. This is partly because IBM usually worsens slowly, so people often adapt without realizing how much strength they have lost until a certain task becomes hard or no longer feels safe.
When to Suspect IBM
Inclusion body myositis should be suspected when a middle-aged or older adult develops slowly progressive muscle weakness in a pattern typical of the disease. Because many other conditions can resemble IBM early on, evaluation by a clinician experienced in neuromuscular disease is often helpful.
For an overview of the key findings used to diagnose IBM, see: Diagnosis of Inclusion Body Myositis.
Revised March 10, 2026