Alopecia areata is an autoimmune condition in which your immune system treats hair follicles as if they’re viruses or other invading germs. It attacks them and causes damage that makes your hair fall out.Most people with alopecia areata develop bald patches on their scalp. But if you have this condition, you can lose hair from any part of your body where hair grows — including your eyebrows, eyelashes, facial hair, and leg hair. Alopecia can cause either small bald patches or total hair loss.Autoimmune conditions can lead to other autoimmune conditions, but having one is not a guarantee that you’ll have others. According to some research from 2010, about 25% of people living with alopecia areata may develop another autoimmune condition. Additionally, a 2021 study reported that people with alopecia areata were almost three times more likely to have another autoimmune disease than people without alopecia.If you have alopecia, a few other autoimmune diseases should be on your radar. Alopecia is most often linked with: autoimmune thyroid diseasetype 1 diabetesvitiligoatopic (allergic) conditions such as asthma, allergic rhinitis, and eczemaWhy do these conditions happen together? Genes are the most likely possible reason. The same genes that are linked to alopecia play roles in causing other autoimmune diseases.Shared genes are the reason autoimmune conditions run in families. Checking in with your parents, siblings, aunts, and uncles may give you a glimpse into your future immune system health.Like other autoimmune conditions, alopecia areata happens because of an immune system misfire. Your immune system’s job is to fight off viruses, bacteria, and other germs. But when you have an autoimmune disease, your immune system mistakes part of your body for a foreign invader and attacks it. In alopecia areata, the attack is aimed at your hair follicles. That’s why this condition causes hair loss. More than 80 different autoimmune diseases exist, but only some of them are linked to alopecia areata.Here is a list of the autoimmune conditions associated with alopecia areata.Research suggests that autoimmune thyroid disease is the most common autoimmune disease linked to alopecia. In one 2013 study that included more than 3,500 people with alopecia, almost 15% also had autoimmune thyroid disease. Your thyroid may be small, but it has some mighty jobs. This butterfly-shaped gland in your neck releases hormones that regulate everything from body temperature to energy use (metabolism), growth, and sleep. Thyroid hormones also help your hair grow, so it makes sense that a problem with this gland can contribute to hair loss.If you have hypothyroidism, it means your thyroid gland is underactive. It’s like your thyroid is releasing its hormones in slo-mo. And when you have less thyroid hormone, all the functions it controls in your body slow down. The main cause of hypothyroidism in the United States is an autoimmune disease called Hashimoto thyroiditis.Levothyroxine is a treatment for hypothyroidism that revs thyroid hormone production back up. It’s a lab-made version of the hormone that your thyroid isn’t making in large enough amounts.Type 1 diabetes is also associated with alopecia areata. In a small 2008 study involving 71 people with alopecia areata, researchers found that 7.1% also had type 1 diabetes. If you have type 1 diabetes, your pancreas doesn’t make enough of the hormone insulin — it may not make any at all. Insulin typically moves glucose (sugar) out of your bloodstream and into your cells for storage, so the lack of insulin makes sugar build up in your bloodstream.Having high blood sugar over a long period of time can damage your nerves, eyes, kidneys, and other organs. That’s why you’ll need to take insulin, count carbs, and check your blood sugar levels often to manage type 1 diabetes.In lupus, the immune system attack isn’t directed at only one part of your body. It’s everywhere, affecting your skin, joints, kidneys, heart, and lungs. Treatment for lupus involves a combo of meds that calms down your immune system and tames inflammation all over your body. While lupus isn’t curable, you can manage it by sticking to the treatment plan prescribed by your rheumatologist.Melanocytes are the pigment cells that give your skin its color. In vitiligo, your immune system damages those cells, leaving you with patches of lighter skin.Some vitiligo treatments restore lost skin color. Others lighten darker areas to make the lighter patches less obvious. “Atopic” is a medical term for conditions involving allergies. Basically, in these conditions, your immune system is overly sensitive to an environmental trigger such as dust or mold. Some research suggests that atopic and dermatological conditions may be linked to autoimmune conditions.In one 2013 study of more than 3,500 people with alopecia areata, almost 40% of the participants also had an allergic condition like eczema, allergic rhinitis, or asthma.Eczema (atopic dermatitis)If the skin behind your knees or on your elbows gets dry and itchy whenever you use a certain soap or laundry detergent, this allergic skin condition could be to blame. But some people with eczema experience flares without any obvious trigger.Special creams, light therapy, and medications that calm your immune system are just a few ways to tame eczema flares. Knowing your triggers and avoiding them is another way to prevent these patches of dry, itchy skin. Allergic rhinitis“Hay fever” is the more common name for this condition. Whatever it’s called, you’ll know it by the sneezing fits, runny nose, and weepy eyes you get when you’re exposed to your allergy trigger. Grass, weeds, mold, and pet hair are just a few of the triggers that can make allergy symptoms go wild. Avoiding your triggers is step one of treatment. But if you do get exposed to them, allergy meds can help put a stop to your symptoms. AsthmaWith this condition, exposure to your allergy trigger makes your lungs swell up and narrow. The result: You wheeze, cough, and gasp for air.Asthma treatments come in two types. Quick-relief medications open up narrowed airways during asthma attacks to help you breathe more easily. Long-term medications keep your symptoms under control by preventing airway swelling.If you have one autoimmune condition, you could develop another one. Alopecia often goes together with autoimmune thyroid disease, type 1 diabetes, lupus, and atopic conditions like asthma and eczema.