Potential Effects of Chronic Pain on Body Weight

Chronic pain can have an impact on an individual’s body weight. While body weight is not affected in all cases; for some, it can lead to weight loss, and for others, it can lead to weight gain.

Weight loss

Severe chronic pain causes the adrenal glands to release excess amounts of the hormones cortisol and catecholamine, which can cause blood sugar levels to fluctuate between hyperglycemia and hypoglycemia. Uncontrolled pain, combined with changes in hormone and blood sugar levels, can lead to loss of appetite, particularly for foods high in protein. Over time, loss of appetite and lack of adequate protein intake leads to weight loss and muscle weakness.

Chronic pain is also linked to weight loss due to inflammation. For example, rheumatoid arthritis is a chronic pain condition in which the immune system attacks the lining of the joints, causing inflammation. This inflammation speeds up the body’s metabolic process, potentially leading to weight loss.

Weight gain

Inactivity is one of the most common causes of weight gain associated with chronic pain. Physical activity may aggravate the pain condition, leading to inactivity, or fatigue may prevent the ability to engage in physical activity. Chronic pain can also lead to depression, which often reduces motivation to engage in physical activity. In addition, weight gain may be caused by “stress eating,” which is sometimes used as a coping mechanism for chronic pain.

Some health conditions that cause chronic pain, such as fibromyalgia, are associated with hormone imbalances or thyroid dysfunction. Elevated levels of the hormone leptin can increase appetite, and thyroid dysfunction can slow the body’s metabolism — both of which can cause weight gain.

In some cases, medications used to treat chronic pain, such as nerve pain or opioid medications, can increase appetite and lead to weight gain. Other medications, such as muscle relaxants, sedatives, and antidepressants, can slow the body’s metabolism, also leading to weight gain.

Actions to take

Individuals with chronic pain should be aware of any unintentional weight loss or weight gain. Concerns should be discussed with a health care provider who can recommend ways to reach or maintain a healthy weight.