Scientists have proposed different ideas about why autoimmune diseases such as multiple sclerosis (MS) are more common in females. Autoimmune diseases develop when the immune system mistakenly attacks the body’s own cells. Some researchers think the higher rates in women are due to sex hormones, genetics, and environmental factors. Others say it’s a mix of these or other unknown factors that affect the immune system.

Overall, men make up one-quarter of people with MS, and research has shed some light on how the disease may affect individuals differently based on biological factors. Here’s how MS symptoms can vary depending on these differences.

1. MS Symptoms Usually Start Later for Men

Most people are diagnosed with MS between the ages of 20 and 40. However, an MS diagnosis for men tends to happen a few years later than it does for women. One possible reason is that more men have primary progressive MS (PPMS).

In fact, PPMS is the only form of MS that men develop at an equal rate to women. Although more women have MS overall, the number of men and women with PPMS is about the same. In PPMS, the disease gets progressively worse over time. It’s not marked by quiet periods of recovery or no disease progression like relapsing-remitting MS (RRMS).

Another key difference between PPMS and RRMS is when the symptoms begin. PPMS usually doesn’t show up until midlife, about 10 years later than relapsing MS (which affects women at higher relative rates).

2. Women Are More Likely To Develop Optic Neuritis

Optic neuritis may affect people with MS when inflammation affects the optic nerve. Studies suggest that men with relapsing MS have a lower chance of developing optic neuritis than women with relapsing MS.

The optic nerve is the pathway that allows communication between the eyes and the brain. As a result, optic neuritis has an impact on eyesight. It usually affects just one eye at a time and comes on suddenly. People with optic neuritis may develop blurry vision, blind spots, and temporary blindness. Optic neuritis can also impair color vision, making vibrant reds look dull. Another possible symptom, called phosphenes, produces flashes of light when moving the eyes.

Optic neuritis can also be painful. Fortunately, it usually goes away by itself after a few weeks. Some women on MyMSTeam have reported longer-lasting symptoms.

“My optic neuritis started with pain, and everything appeared to be a glare. Then, color washed out, and the center of my vision seemed blocked. It’s been three months, and it hasn’t really improved,” shared one member. If optic neuritis seems to be an ongoing problem, doctors may prescribe steroids to help reduce inflammation and relieve symptoms faster.

3. Men Decline Faster Physically and Mentally

Both men and women with MS experience changes in the body and brain that affect their daily lives and independence. When comparing men and women with relapsing MS, studies show that men have an increased risk of motor impairments. Men with MS become disabled more quickly, showing symptoms like difficulty walking and the need for a cane or other assistive devices.

Many factors may contribute to the disability progression seen in men with MS. Men with MS have more neurodegeneration, which is damage to the brain and nervous system. They also tend to have more cortical lesions (lesions on the surface of the brain), ongoing brain inflammation, and are more likely to develop neuron damage.

Spasticity and ataxia (lack of muscle control) are common symptoms for men with MS. Men on MyMSTeam have shared how motor symptoms affect them. “Tremors and cramping in my legs happen involuntarily,” one member shared. “I’m in a wheelchair, and they will lift my leg completely off the pedals. Sometimes, in my recliner, my leg and back will tense up and completely lock up my body.”

Another shared, “I’ve had a tremor in my left hand for about three years, and it has become pretty aggravating. I can’t eat out. It’s embarrassing. Anyway, I had an attack a few nights ago while sitting in my recliner. I wondered whether that was related to MS.”

Fortunately, doctors have several options for prescription drugs that help reduce spasticity. Ataxia can cause balance issues and put men with MS at risk for injury. Physical therapy focusing on balance and motor skills is the primary treatment. Low-dose anticonvulsants can also help in certain cases.

4. Women Recover Better After Relapses

According to research from the Journal of Personalized Medicine, men with MS don’t recover as well as women do after relapses. MS studies on mice show that female rodents are better at repairing damaged myelin after an MS flare-up. This slower recovery in men may lead to more severe disability over time. Men also transition to secondary progressive MS (SPMS) at higher rates and faster than women with MS.

Comorbidities are coexisting conditions that happen along with MS. Just like the general population, people with MS may develop comorbidities like heart disease and diabetes. These additional health problems can make MS worse and harder to treat.

Men with MS are more likely to have additional health conditions at the same time, known as comorbidities, such as anxiety, depression, diabetes, and epilepsy. One study found that men diagnosed with MS had a 48 percent higher rate of high blood pressure compared to men without MS. In contrast, women with MS were 16 percent more likely to have high blood pressure than women without MS.

Men with MS must be especially mindful to care for their physical and mental health. Although it’s easy to become laser-focused on MS alone, these other health issues can play a major role in the MS disease course and overall quality of life.

5. Sexual Dysfunction Affects Both Groups

Sexual problems aren’t always discussed, but they can significantly affect the lives and relationships of men and women with MS. Sexual issues seem to impact men with MS at a slightly higher rate. Some estimates say that 50 percent to 90 percent of men with MS have sexual problems compared to 40 percent to 80 percent of women.

Trouble getting an erection, inability to orgasm, and a lack of interest in sex are symptoms that men with MS may face. Some of these issues are caused directly by MS lesions. Other times, medication side effects, comorbidities, or the psychosocial aspects of MS are responsible.

Open communication with the health care team is crucial to help men and women address the undertreated sexual dysfunction that often happens with MS. While no two people with MS are exactly alike, there’s no shame in speaking with your health care provider about how MS affects your life.

Talk With Others Who Understand

On MyMSTeam, the social network for people with multiple sclerosis and their loved ones, more than 216,000 members come together to ask questions, give advice, and share their stories with others who understand life with multiple sclerosis.

Were you surprised by any of these differences between men and women? What symptoms of MS are most significant for you? Share your thoughts in the comments below, or start a conversation by posting on your Activities page.