If you find yourself not feeling hungry or don’t eat as much as you used to, you may wonder if your multiple sclerosis (MS) is to blame. Loss of appetite can be quite challenging over a period of time. The effects of not eating –– including fatigue, weight loss, weakness, and mood changes –– can affect your health and quality of life.

Several members of MyMSTeam have described their experiences with loss of appetite and how it’s affected them. “All I want to do today is sleep. No interest in anything. No appetite,” one member mentioned.

Another member asked, “Does anybody suffer from loss of appetite? I have had no appetite for weeks. I researched it and it’s a symptom.”

A third member described how severe their condition became. “They threatened me with a feeding tube because I have no appetite, optic neuritis, weakness all over, and a dead right leg.”

Read on to learn more about the different causes of loss of appetite in MS, the influence it can have on your health, and when to talk to your doctor.

How Common Is Loss of Appetite in MS?

It’s unknown overall how many people with MS experience feelings of not being hungry or not wanting to eat consistently. It’s a difficult number to estimate because there are many different causes of decreased appetite that are related to MS. For example, about nearly two-thirds of people living with MS struggle with a gastrointestinal problem. Depending on what the problem is and its severity, it can cause people to skip meals regularly or not want to eat.

Causes of Loss of Appetite in MS

There are many different reasons that could explain why you’ve lost your appetite while living with MS. Understanding the potential cause is the key to addressing the root of the problem. The most common causes include:

• Fatigue
• Cognitive impairment
• Feelings of nausea
• Digestive (gastrointestinal) problems
• Pain
• Stress
• Mood changes, especially depression
• Certain medications
• Swallowing problems
• Relapse

Fatigue is very common in MS, affecting 75 percent to 90 percent of people with the condition. Severe fatigue can make someone too tired to eat or even forget to eat. When this happens regularly, it can lead to unintentional weight loss.

Some people with MS have symptoms from relapses that affect their swallowing and chewing muscles, making eating a challenge and sometimes even a risk. The medical term for this condition is dysphagia. About 20 percent of people with MS report symptoms of dysphagia. If dysphagia is severe, it can lead some people to choke or spit out their food. If you’re not getting enough nutrition, it’s possible to lose weight over time.

About 30 percent of people with MS report symptoms of indigestion. Indigestion can cause feelings of fullness or abdominal pain, resulting in not wanting to eat. Gastroparesis –– when food sits in the gut due to paralysis –– can cause people to feel full, leading to severe weight loss over time if meals are skipped.

Some medications may cause you to lose your appetite. Examples include certain antidepressants, such as bupropion (Wellbutrin) and stimulant medications prescribed to fight chronic fatigue, such as methylphenidate (Ritalin).

Certain disease-modifying therapies (DMTs) for MS are known to cause nausea as a side effect, including teriflunomide (Aubagio), dimethyl fumarate (Tecfidera), and ocrelizumab (Ocrevus).

Additionally, medications for mood disorders, including fluoxetine (Prozac), can cause feelings of nausea.

Dizziness and vertigo, which some people with MS experience, can lead to nausea. Nausea can be very uncomfortable and may make you want to skip your next meal.

Living with MS can be very stressful. Stress and mental health disorders, such as depression, can affect appetite. People react to stress differently, and some people living with depression don’t have the energy to eat or simply don’t feel hungry. Living with pain is also linked to losing your appetite.

In some cases, you may have MS and lose your appetite, but the cause of your loss of appetite might not be from MS. Other health conditions, including thyroid disorders, hormonal disturbances, eating disorders, infectious diseases, cancer, and chronic illness can all cause unintentional weight loss.

Effects of Loss of Appetite

Losing weight when you’re not trying to can have damaging effects on your health and lifestyle, especially if you have MS.

One member described their experience. “Everyone keeps telling me how great it is that I’ve lost weight and how I must be feeling so much better. It’s kind of them to say — but I’m not. I’m exhausted from not getting enough calories in, and my body doesn’t have fuel to burn," they wrote. "My stomach doesn’t rumble, feel hunger pangs, or otherwise remind me that I need to sit down and eat. I can have something delicious in front of me that looks and smells SO good, and I take two bites and want to push it away. Why is food suddenly gross?”

Not eating over a prolonged period of time can be debilitating. It’s essential to understand what the impacts can be on your daily life and how to prevent them.

Unintended Weight Loss

A loss of appetite that leads to unintentional weight loss can have many effects on you and your quality of life, including:

• Fatigue or loss of energy
• Diarrhea or constipation
• Nausea or vomiting
• Decreased immunity
• Loss of muscle strength
• Changes to your skin, hair, and nails
• Higher risk of pressure sores

If you are losing weight unintentionally, you’re likely not getting enough nutrients from the amount of food you’re eating. If you are undernourished (not eating enough nutrients) or malnourished (not getting the right types of nutrients) — especially over a long period of time — your immune system may weaken. This can make you more susceptible to other illnesses.

Malnutrition can also affect your cognitive abilities, including your attention span, level of energy, and ability to concentrate. Fatigue — while it can have many different causes — can likewise seriously affect your ability to participate in daily activities, work, and relationships. Malnourishment can also reduce your muscle strength. Over time, if the muscle loss is significant, it can sometimes affect your ability to walk and participate in daily physical activities.

If you’re using a wheelchair or must stay in bed due to your MS symptoms, you may be at an increased risk of developing pressure sores. Pressure sores, sometimes called bedsores or decubitus ulcers, develop when skin is exposed to prolonged, leading to skin breakdown and wounds. Sometimes, they may only take a few hours to develop. People who are thinner are more likely to develop pressure sores.

Some pressure sores never heal, even with treatment. You need proper nutrition for good wound healing. If pressure ulcers are untreated or fail to heal, several serious complications can occur, which can be life-threatening. Doing everything possible to reduce the risk, including maintaining a healthy weight, is critical.

Losing Weight in MS

If you have MS and want to lose weight, prevent weight gain, or fight obesity, there’s a great deal of information available about living an active lifestyle and healthy eating. Your first step, however, should be to seek advice from your health care provider.

When To Speak to Your Doctor

If you’re losing weight and you’re not sure why, speak to your doctor as soon as possible. This is especially true if your weight loss is accompanied by fever, night sweats, cough, bone pain, or other new symptoms. Unexplained weight loss or a lack of appetite can be a sign of another medical condition, ranging from thyroid problems to cancer.

When you visit your doctor, the following may be included in your evaluation:

• A review of your medical, surgical, and mental health history
• A review of the medications you’re taking
• A physical examination
• A conversation about your dietary habits and any changes
• Possible blood testing
• Swallowing test (if there is concern about dysphagia)
• Additional tests or imaging depending on the possible diagnosis

Once your doctor figures out the cause of your loss of appetite, treating the underlying problem is the priority. Depending on the cause, changes to your medications, nutritional rehabilitation with a dietitian, mental health counseling, or food supplementation may be necessary.

Talk With Others Who Understand

MyMSTeam is the social network for people with MS and their loved ones. On MyMSTeam, more than 198,000 members come together to ask questions, give advice, and share their stories with others who understand life with MS.

Are you living with MS and worried about a loss of appetite? Did you find this article helpful? Share your experience in the comments below, or start a conversation by posting on your Activities page.