What should I do about my TSH of 8.7 with a fast heartbeat?

Question

Hello doctor,

My recent TSH level was 8.7, so I started taking levothyroxine 50 mcg. In the first week, I felt very lightheaded. Since then, I have had ongoing palpitations and a faster heart rate, which is not normal for me.

I also wake up every morning with palpitations, and they usually last all day. I wanted to let you know and ask for your advice on what to do next.

We would greatly appreciate any guidance you can provide.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com

I read your query and understand your concern.

I want to reassure you that your symptoms are significant and that I understand your worries. Levothyroxine is the usual treatment for hypothyroidism, which is indicated by a TSH (elaborate) level of 8.7mIU/L. But you need to pay close attention to the symptoms you've had since starting the drug.

Feeling lightheaded in the first week, along with ongoing palpitations and a faster heart rate, especially in the morning, could mean your body is reacting to the dose. This sometimes happens if the dose is a bit too high or if you are sensitive to thyroid hormone changes. These symptoms can sometimes feel like those of an overactive thyroid.

Other things that can play a role include anxiety from hormone changes, dehydration, low blood sugar in the morning, or, less often, a heart rhythm problem that becomes more noticeable as your metabolism speeds up. If your morning palpitations last all day, this is not a usual mild side effect and could mean your thyroid hormone levels are higher than they should be.

Please reach out to your doctor soon to talk about your symptoms and set up new thyroid tests, including TSH, Free T4, and maybe Free T3. Depending on your results and how you feel, your doctor might lower your dose, for example, from 50 mcg to 25 mcg, or change how you take the medicine.

While you wait, try to avoid caffeine and other stimulants. Take your medication on an empty stomach with just water, and keep an eye on your heart rate if you can. If your resting heart rate often goes over 100 beats per minute, let your doctor know.

If you have pain, trouble breathing, fainting, or a very fast or irregular heartbeat, please get medical help right away.

Sometimes the starting dose can be a bit high, depending on your weight and how sensitive you are, especially if your hypothyroidism is mild. This can be managed and usually gets better once the dose is adjusted.

Please feel free to reach out if you have any further questions.

Thank you.