Recent research suggests that more Americans have blood markers signaling autoimmunity, or that their body is making antibodies that could fight a person's own immune system, and that could translate to a rise in autoimmune disorders. If that made your brain hurt, just know that autoimmune diseases are becoming more and more common.
“An autoimmune disease is any condition that causes your own immune system, which is designed to fend off foreign bodies, mistakenly attacks parts of your own body,” says Deepa Kirk, M.D., associate professor of medicine and medical director of the UNC Hospitals Diabetes and Endocrinology Clinic at Meadowmont.
Another annoying fact: Autoimmune diseases are more common in women than in men, and they usually start during the childbearing years, according to the U.S. Department of Health and Human Services.
In most cases, it’s not totally clear why someone develops an autoimmune disease. Family history increases your risk of developing one, people with certain ethnic backgrounds may have higher risks of some conditions, and having one autoimmune disease makes you more likely to develop others. Overall, there’s really no way to see into the future and either predict or prevent one—at least not yet.
How that disease makes you feel depends on the condition you've got, but one thing that many autoimmune diseases share is their tendency to mess with your weight. And a lot of the medications given for autoimmune diseases can also screw with the scale.
Here are seven autoimmune conditions that can make you gain weight or lose weight, and what you need to know about each one.
Type 1 Diabetes
You may not know this, but Type 1 diabetes is, in fact, an autoimmune condition. It happens when the immune system attacks the part of the pancreas that makes insulin, Dr. Kirk says. Insulin is a hormone that’s responsible for converting sugar in food into energy our bodies can use—essential for keeping us energized and nourished and also for keeping blood sugar levels normal. With Type 1 diabetes, the pancreas either produces zero insulin or just a teensy bit—not nearly enough to keep blood sugars in check.
If it's untreated, it can cause unexpected weight loss. “Without insulin, even if you’re digesting food and breaking down glucose, the glucose will just swim around in the bloodstream and you’ll pee out as much as you can,” Dr. Kirk explains. Insulin also plays a role in breaking down fats and proteins and transporting them into the right cells in the body, she adds. “Your body thinks you’re starving even when eating because it can’t hold onto and use the calories.”
It can take months or years for enough of the pancreas to be destroyed to cause symptoms, according to the Centers for Disease Control and Prevention. But once symptoms pop up, they include having to pee a lot, always being thirsty and hungry, blurry vision, feeling tired, and unexplained weight loss.
If you've got it, you have to take insulin, says Caroline Apovian, M.D., co-director of the Center for Weight Management and Wellness in the Division of Endocrinology, Diabetes, and Hypertension at Brigham and Women’s Hospital. This can either be via injections or wearable devices that deliver insulin when your blood sugar goes up.
One of the main functions of thyroid hormone, made by (you guessed it) the thyroid, is to regulate metabolism, Dr. Kirk says. "If you don't have enough of the hormone, your metabolism typically slows down.” What she’s explaining is hypothyroidism.
Certain surgeries and medications can mess with the thyroid and cause it to slow down, but the most common cause of hypothyroidism is an autoimmune disease called Hashimoto’s thyroiditis.
In Hashimoto’s, the immune cells kill off thyroid cells, which causes the gland to be underactive, Dr. Apovian says. Metabolism slooooows way down, and weight gain is common, but it typically happens gradually over time. Other symptoms include feeling colder, getting tired easily, dry skin, forgetfulness, depression, and constipation, according to the American Thyroid Association. “For many women, it usually starts in their 20s, and if you don't catch it right away you can get really sick,” Dr. Apovian says.
There’s no cure for autoimmune hypothyroidism, but it can be controlled by taking medication that gets your thyroid hormone up to healthy levels.
This is a condition where there is too much thyroid hormone in the blood, which ultimately leads to unintentional weight loss despite having a hearty appetite. It can have a few potential causes, but the most common is Graves’ Disease, an autoimmune condition that prompts the thyroid gland to make extra thyroid hormone. According to the American Thyroid Association, antibodies in the blood turn on the thyroid and cause it to grow and secrete too much thyroid hormone.
This essentially kicks your metabolism into overdrive, Dr. Kirk says. “The classic symptoms we see, especially in young people under 40, are being more hungry and eating more but losing weight,” she says. (Older people who develop Graves’ typically have an increase in appetite but won’t experience the same noticeable weight loss.) Other symptoms of Graves’ include being sweaty all the time, anxiety, tremors, and heart palpitations, Dr. Kirk adds.
If it goes unchecked, hyperthyroidism can make you feel like crap. “It’s not pleasant—you lose fat and muscle,” Dr. Apovian says. “You get pretty sick.”
Hyperthyroidism is treated with medications that work to suppress thyroid hormone and stabilize levels. These sometimes end up causing hypothyroidism, and then your doctor will switch you to a thyroid hormone supplement—hypo is easier to manage long-term, so it’s sort of the lesser of two evils.
The antithyroid medications used to slow down thyroid hormone production can end up causing weight gain, Dr. Kirk says, especially if you’ve gotten used to eating according to your revved-up hunger while your metabolism was in overdrive.
Addison’s disease, a form of adrenal insufficiency, happens when the immune system destroys part of the adrenal gland—which is responsible for making certain hormones, including cortisol, Dr. Kirk explains. You may know it as the “stress hormone,” but cortisol actually does loads of things in the body, including fighting infection, regulating blood sugar, maintaining blood pressure, regulating metabolism, and yes, helping our bodies respond to stress, according to the U.S. National Library of Medicine. If you don’t have enough, you can get really sick.
The most common symptoms of Addison’s disease are fatigue, muscle weakness, loss of appetite, weight loss, and abdominal pain, according to the National Institute of Diabetes and Digestive and Kidney Diseases. “Weight loss can be dramatic,” Dr. Kirk adds. In milder cases, it can go undiagnosed for some time. In more extreme cases, your hormones can tank enough to cause a legit emergency situation.
Addison’s is treated by supplementing with the hormones your body isn’t making enough of. “People feel much better as soon as you replace the hormones,” Dr. Kirk says. The medications given for Addison’s are different types of steroids—basically, drugs that mimic the hormones your body needs—which can cause weight gain. It’s a common side effect of steroid medications, but also, it can be difficult to nail the perfect dosing for people with Addison’s, Dr. Kirk says. Hormone levels in the body change constantly (seriously, from minute to minute sometimes), so your doc will want to give you the lowest dose necessary while also making sure you definitely have enough to avoid dangerously low levels.
This condition causes an immune reaction to gluten, the protein found in wheat, which damages the small intestine. Not everyone will experience symptoms, but for those who do, symptoms can include bloating, chronic diarrhea, constipation, gas, nausea and vomiting, and abdominal pain, according to National Institute of Diabetes and Digestive and Kidney Diseases.
Weight loss can happen indirectly, as a result of these less-than-stellar symptoms. If you don’t know you have Celiac, but know that eating leaves you feeling all kinds of awful, you may lose your appetite or avoid a lot of foods. Small intestine damage may also cause some people to be lactose intolerant—which has similar rough symptoms.
Small intestine damage can also make it hard for your body to absorb nutrients from food, according to the U.S. National Library of Medicine.
The only way to treat Celiac disease is to avoid gluten entirely. That (tragically) means no bread, pasta, bagels, cake, and more foods and drinks with wheat in them—gluten-free versions are fair game, of course.
Crohn’s Disease and Ulcerative Colitis
Crohn’s and ulcerative colitis (UC) are collectively known as irritable bowel disease, or IBD. These autoimmune diseases cause inflammation in various parts of the digestive tract. Both commonly cause weight loss and malnutrition. Inflammation in the small intestine can make it difficult to properly digest food and absorb nutrients, and inflammation in the large intestine makes it difficult to absorb water and electrolytes, according to the Crohn’s and Colitis Foundation.
On top of that, the symptoms can mess with your weight, Dr. Apovian says. “Abdominal pain and diarrhea are typically associated with weight loss, but depending on what you can eat, you may gain weight,” she says. If you have abdominal pain after eating healthy foods like fruits and veggies, you may avoid them and eat a lot of unhealthy foods that don’t cause pain.
Some people can control their IBD with medications, but some might need surgery to get everything under control.
RA and similar joint diseases cause fatigue and stiffness in the joints, which can make it hard to do daily activities, Dr. Apovian says. This can lead many people to avoid physical activity, resulting in weight gain.
This happens when the body attacks healthy tissues throughout the body, mainly in the joints, and most commonly, the hands, wrists, and knees, according to the CDC. It causes inflammation, pain, and long-term joint damage if it’s not controlled with medication.
Luckily, in recent years, new medications that fight this immune reaction have made it easier to treat, Dr. Apovian says. Hey, that's not nothing!
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.