Multiple sclerosis (MS) is an autoimmune disease in which the body’s immune system attacks and destroys myelin, a fatty substance that covers nerve fibers and is critical for their electric function. The resulting inflammation interferes with the ability of the nerves to send electrical signals between the brain and spinal cord and other regions of the body, and, in turn, the loss of effective nerve communication leads to disease symptoms.
Specific symptoms will vary person-to-person, depending on factors like where in the body the nervous system is being damaged. The severity of symptoms also varies widely, meaning that everyone with MS will have a different experience.
The inflammatory attack on the nervous system can cause disease relapses (also called exacerbations or flare-ups): times when one or more symptoms appear or get substantially worse. To constitute a relapse, these symptoms must last for at least a day, and may continue for weeks or months.
The most common symptoms of multiple sclerosis include:
Muscle spasms and spasticity, an abnormal increase in muscle tone or stiffness that affects muscle movements, are among the most common MS symptoms. It is estimated that 60%–90% of MS patients will experience spasticity at some point.
Damage to parts of the brain that help to regulate balance can cause dizziness, a range of sensations that include feeling light-headed, faint, off-balance, and disoriented. Some people with MS experience vertigo, a more severe form of dizziness that is characterized by an intense sensation of spinning, which can lead to balance and vision problems, motion sickness, nausea, and vomiting.
As a result of spasticity and balance problems, as well as fatigue, muscle weakness, and other symptoms, many people with MS experience difficulty walking, especially in latter stages of the disease.
Tremors (uncontrolled shaking) can occur in some people with MS. Additionally, muscle weakness and neurological problems in the face and jaw can lead to abnormal speech or dysphagia (swallowing problems).
Fatigue is defined as mental or physical exhaustion that prevents a person from performing everyday activities. It is one of the most common symptoms in MS, affecting about 80% of patients. Among MS patients, fatigue is linked to under-employment, early retirement, and reduced quality of life.
MS-related fatigue could be “primary,” also called lassitude, which is a direct result of myelin damage. This fatigue is unique to MS and different from that experienced by people without MS: it is sudden, more severe, aggravated by heat or humidity, and unaffected by restful sleep. By contrast, “secondary” MS-related fatigue is an indirect result of other MS symptoms, such as depression, stress, recent relapses, side effects of medication, and sleep disorders.
MS fatigue can be managed through medication and/or lifestyle changes (such as exercise, diet, naps, and cold showers). Experts also recommend evaluating and treating any secondary causes (such as drug side effects, depression, and sleep disorders) to help manage fatigue in MS.
Up to two-thirds of people with MS experience a wide range of pain-related symptoms, from headache and back pain to painful tonic spasms (cramping and pulling pain), and continual burning pain in the extremities.
Neuropathic pain, where the sensation of pain is caused by damage to the parts of the nervous system normally responsible for detecting pain, is the most common type of pain experienced by people with MS. It typically occurs in the legs and is felt as a persistent and burning pain.
Musculoskeletal pain, where pain occurs as a result of abnormal muscle activity like spasticity, can occur in MS. Paroxysmal (sudden) pain is less common, but is most frequently experienced by MS patients as facial pain caused by trigeminal neuralgia (a condition characterized by damage in the nerve that carries information from the eyes, cheek, and jaw to the brain).
Combining good mental health practices with exercise, staying active socially, body massages, chiropractic treatments, hydrotherapy, acupuncture, and/or medications can help to manage MS pain and improve quality of life.
Most common analgesics (painkillers) are usually not enough to ease pain caused by nerve damage in the central nervous system, so drugs that treat seizures, antidepressants, and some benzodiazepines are among the common first choices for pain management in MS.
Other abnormal sensations
Beyond pain, people with MS may experience other abnormal sensations, like numbness, tingling, or uncontrolled itching. They also may experience dysesthesia, which is an unpleasant and possibly painful sensation often described as a burning and aching feeling or, if affecting the trunk, a “girdling” sensation across the body (popularly known as the “MS hug”).
Another abnormal sensation that can occur in people with MS is Lhermitte’s sign: a sudden sensation that feels like an electric shock passing down the back of a person’s neck and into the spine, which may then radiate out into the limbs. Lhermitte’s sign is usually triggered by bending the head forward towards the chest.
People with MS also often experience heat intolerance. Heat, in whatever form, can cause MS symptoms to worsen. This can be triggered by anything that raises the body’s temperature, including exercise, sunbathing, hot baths, and fevers. Common effects of heat sensitivity include increased fatigue, blurred vision, loss of balance, and/or memory and concentration difficulties.
Bladder, bowel, and sexual complaints
People with MS often experience bladder problems, such as frequent urination or difficulty urinating, and bowel problems, like constipation.
Sexual health problems are also common in MS. Damage to nerve impulses can directly affect arousal and orgasm, and other symptoms — from emotional problems to fatigue to movement difficulties — can cause challenges in sexual relationships.
People with MS may experience decreased or painful genital sensation, and may have difficulty achieving orgasm. Erectile dysfunction and vaginal dryness are also common. MS does not directly affect fertility, though symptoms like erectile dysfunction may still pose obstacles for people trying to have children.
Emotional and cognitive problems
Mental health problems, such as anxiety and mood swings, are common in people with MS.
Depression — characterized by long periods of sadness, apathy, and other negative thoughts — is especially common. Depression occurs more frequently in MS than in the general population or in other diseases. It can be directly caused by the underlying damage to the nervous system, but some medications can also contribute to depression in certain individuals.
Some people with MS may experience pseudobulbar affect, a sudden burst of uncontrollable laughter or crying, often for no apparent reason.
Damage to the nervous system can cause difficulty with thinking or reasoning, learning, problem-solving, and planning. More than half of MS patients will experience problems with cognition. These changes are usually mild, but more severe cognitive impairment can occur.
Vision and hearing problems
MS can cause damage to the optic nerves, which connect the eyes to the brain. Consequently, vision problems, such as blurred vision, double vision, temporary loss of vision, eye pain (especially when moving the eye), or color blindness, may develop in MS.
Hearing loss can occur in MS, though less frequently than vision problems.
Last updated: June 28, 2021
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