The Causes of Pain:
All 18 Explained.

When people think of pain, musculoskeletal pain is usually the first thing that comes to mind — it's the most common type of pain.

Muscles repeatedly contract and relax. Contraction happens instantly without needing energy, but relaxation requires energy.

That's why cooling down with stretching after exercise is important — it supplies energy to the muscles and helps them return to their original length.

Skipping this cool-down can cause muscles to shorten, leading to muscle pain and joint problems.

As we age, growth hormone levels decline, which accelerates muscle shortening — one reason pain conditions become more common with age.

[Examples of trauma] Falling while playing soccer, getting hit by a ball while playing baseball, spraining something during judo, or breaking a bone during a combat sport — any of these injuries can cause musculoskeletal pain.

Injury rates increase with age, which is one reason pain conditions become more common as we get older.

When an injury causes deformity of a joint, bone, ligament, tendon, or cartilage, the resulting postural imbalance can become an ongoing source of pain.

Surgery for various conditions, not just trauma itself, can also lead to postural imbalance.

Pain can result from what's commonly called "a cold with body aches."

A cold usually clears up after 7 to 10 days, and the accompanying body aches fade along with it.

However, antibodies that remain after a cold can sometimes attack the body's own tissue, not just the cold virus.

Antibodies that attack the body's own tissue are called autoantibodies. When these accumulate over the years, they can cause a range of conditions.

Autoimmune diseases, commonly known as rheumatic disease, are also a cause of pain.

Rheumatoid disease occurs when respiratory or digestive infections trigger an immune response, and some of the resulting antibodies end up attacking the body's own tissue.

In addition to bacterial infections, medications or minerals entering the body can also trigger antibody production.

Just as antibodies against bacteria can turn into autoantibodies, antibodies formed against medications or minerals can also end up attacking the body's own tissue.

As we age, exposure to infections and medication use both increase, which is one reason disease rates rise with age.

Tumors can be either benign or malignant.

Tumors can form when cell division goes wrong for some reason.

The likelihood of this happening also increases with age.

Blood disorders can include clotting problems or anemia.

In young women especially, normal blood clotting is needed during menstruation. If clotting and fibrinolysis aren't properly balanced, this can lead to uterine diseases.

Bleeding can also lead to anemia.

Blood-related conditions such as clotting problems and anemia can also become more common with age.

Age-related hormonal changes include menopausal symptoms in women after menopause; men experience hormonal changes around the same life stage as well.

Antidiuretic hormone, which is closely linked to nighttime urination, can decline after age 50. If nighttime urination becomes a problem, it's worth checking both prostate enlargement and antidiuretic hormone levels.

Pregnancy also causes dramatic hormonal shifts. Of the eight pituitary hormones, prolactin rises sharply during pregnancy while the others drop significantly.

After childbirth, pituitary hormone levels should return to normal. If they don't fully recover, health problems can follow. Growth hormone is a key example — it's needed for the liver to produce proteins, lipids, and carbohydrate complexes, so abnormal growth hormone levels can impair liver function.

Diabetes is technically an endocrine condition, but it's covered separately here given how common it is.

The link between diabetes and pain is easy to understand once you know that neuropathy is one of diabetes's three classic symptoms.

Diabetes also becomes more common with age, contributing to the rise in pain conditions as we get older.

Common sleep disorders include snoring and sleep apnea.

When oxygen supply drops during sleep, damaged tissue can't repair properly, which can lead to pain.

See our Sleep & Pain page for more details on sleep disorders and polysomnography.

Sleep disorders such as snoring also become more common with age, contributing to the rise in pain conditions in older adults.

Eye conditions can cause eye pain.

Middle ear infections can cause ear pain.

Rhinitis or sinusitis can cause pain in the cheek area, where the sinuses are located.

Inflammation in any of these areas can lead to pain.

Conditions such as sinusitis also become more common with age, likely contributing to the rise in pain conditions in older adults.

Left-sided chest pain from angina occurs when the coronary arteries supplying the heart become blocked. It's severe enough to have its own name in Korean medicine — "jinsimtong," or "true heart pain."

Beyond this, blocked arteries — from high cholesterol or other causes — can cause pain in any tissue by cutting off its blood supply.

A blocked vein can cause the same result. When venous return is impaired, the amount of blood that can be supplied is limited even if the artery itself is normal, which can lead to pain.

Cardiovascular disease also becomes more common with age, likely contributing to the rise in pain conditions in older adults.

Inflammation or masses in the respiratory system — such as pleurisy from tuberculosis, pneumonia, or bronchitis — can cause pain.

More detail is provided elsewhere when discussing common respiratory conditions such as colds, emphysema, and bronchiectasis.

Just as a chronic cough from bronchitis is often seen as a sign of aging, respiratory conditions in general become more common with age, likely contributing to the rise in pain conditions.

Digestive organs such as the stomach, small intestine, and large intestine can cause pain when overly distended.

Pain can also be the first symptom of conditions such as hepatitis.

Digestive conditions such as indigestion also become more common with age, likely contributing to the rise in pain conditions in older adults.

Shingles, a viral condition, is a leading example. Shingles is known to occur when immunity weakens, and immunity is known to decline with age.

This is why shingles also becomes more common with age, likely contributing to the rise in pain conditions.

Urinary tract pain, most notably from kidney stones, is known for its intensity.

This condition also becomes more common with age, likely contributing to the rise in pain conditions.

Menstrual cramps: pooling of menstrual blood during a woman's period can cause pain.

A blood clotting disorder — caused by a deficiency or imbalance of clotting factors and fibrinolytic factors made in the liver — can trigger menstrual cramps.

The rate of pain and conditions from menstrual blood pooling also increases with age, likely contributing to the rise in pain conditions.

Some genetic conditions are diagnosed late, or the genetic defect is mild enough to go unnoticed until adulthood.

The prevalence of pain related to genetic syndromes is also known to rise with age, likely because many patients with genetic conditions die at a younger age.

Common examples include pain that develops as a side effect of surgery, or pain from medications required for chronic conditions such as diabetes, high blood pressure, or high cholesterol.

Serious intractable conditions such as Parkinson's disease, stroke, or Agent Orange-related aftereffects can also cause pain.

As we age, the likelihood of surgery, chronic disease, and serious intractable illness all increase, likely contributing to the rise in pain conditions.