Causes

Several different things can interfere with your thyroid function or levothyroxine treatment and trigger a flare-up of Hashimoto’s disease, including:

Some medications or supplementsCertain dietary nutrientsHigh stress levelsIncorrect medication dosage

In order to treat your Hashimoto’s more effectively, it’s important to figure out what’s causing your symptoms to act up.

Medications or Supplements

A lot of common medications and nutritional supplements can interfere with how your body absorbs synthetic levothyroxine. Some drugs can also impact the way your body metabolizes thyroid medication. In either case, your body doesn’t get enough of the drug to keep your autoimmune thyroid disease symptoms at bay. 

According to studies, including one of more than 5,000 people on thyroid hormone therapy, numerous drugs can interfere with levothyroxine absorption, including:

Antacids that contain aluminum such as Alamag, Maalox, Mylanta, and Rulox Carafate (sucralfate) Questran (cholestyramine) Renagel, Renvela (sevelamer) Cipro, Proquin XR (ciprofloxacin) Evista (raloxifene) Alli, Xenical (orlistat) Proton pump inhibitors such as: Prevacid (lansoprazole), Prilosec (omeprazole), and Nexium (esomeprazole)

Drugs that can alter the way your body metabolizes levothyroxine include:

Carbatrol, Tegretol (carbamazepine) Phenobarbital Dilantin (phenytoin) Gleevec (imatinib) Estrogens such as Premarin, Estrace, Estratab Cordarone, Pacerone (amiodarone) Rifadin, Rimactane (rifampicin)

Nutritional supplements that can interfere with thyroid hormone replacement include:

Calcium carbonate Iodine Iron Multivitamins containing calcium and iron Supplements containing soy extracts

Stress

Stressful events or chronically high stress levels can aggravate your immune system and increase autoimmune activity. Research has linked stress to lower thyroid hormone levels as well. Given this one-two punch, it’s possible that stress could cause a Hashimoto’s flare-up.

Don’t just assume your flare-up is stress-related, though. If you have ongoing symptoms of Hashimoto’s, let your healthcare provider know so they can check for other possible causes.

Incorrect Dosage

You may be having Hashimoto’s symptoms because you’re not on the right dosage of levothyroxine. When you first begin treatment for hypothyroidism, it’s common to need a few adjustments to your dosage before you reach a symptom-free state.

Early on, or after a dose adjustment, your healthcare provider may test your thyroid hormone levels every six to eight weeks. Once your ideal dosage is reached, you may only need to be tested once a year.

However, if you begin having symptoms of low thyroid hormone, you may need a higher dosage and the associated regular testing until symptoms are once again under control.

Symptoms

In a Hashimoto’s flare-up, you’ll begin having symptoms of hypothyroidism, which include:

Fatigue Weight gain Frequently feeling cold Dry skin and hair Muscle and joint aches Depression Constipation Memory problems Irregular menstrual periods Slow heart rate

When to See a Healthcare Provider

Flare-ups shouldn’t happen when you’re on the correct dose of levothyroxine. Any time you have a resurgence of Hashimoto’s symptoms, you should let your healthcare provider know. They may want to change your dosage, look for things that could be interfering with your treatment, or test for other potential causes of your symptoms.

Treatment

Treatment for a Hashimoto’s flare-up depends on what’s behind the increase in symptoms.

Timing Is Key

If a medication or supplement is hampering your body’s ability to utilize levothyroxine, you may need to change the timing of your medications. Sometimes, simply taking the interfering medication at least an hour after your levothyroxine will allow your body to fully absorb the medication. If you take your thyroid drug in the morning, you may have better luck taking it at night.

The timing of your thyroid medication can be affected by a lot of different factors, including other drugs you take and even what you eat for breakfast, so before changing the time of day you take your levothyroxine, talk to your healthcare provider about it.

Other Approaches

There are other ways to manage a Hashimoto’s flare-up:

In some cases, your healthcare provider may advise you to stop a medication or replace it with a different drug. With proton pump inhibitors, research shows that taking an oral levothyroxine solution instead of tablets may improve absorption. If you have a nutrient deficiency, you may need to take supplements or change your diet to bring levels up and improve your thyroid function. For stress-related thyroid flare-ups, some preliminary research suggests that mindfulness meditation may improve immune system function.

A Word From Verywell

Regardless of what’s causing your Hashimoto’s symptom flare-up, a trip to the healthcare provider’s office is a good place to start. With their help, you can investigate possible causes of your low T4 levels and implement the right solution. Successful thyroid disease treatment is a balancing act and sometimes tricky, but once you get things back in balance, you should be feeling and functioning better again.