Lifestyle

6 Signs of Low Thyroid Most People Blame on Getting Older

By Erica Coleman · October 14, 2026

Feeling more tired than you used to, or reaching for a sweater when everyone else is comfortable, can seem like part of the deal after 50. Sometimes it is. But some of those changes can also point to a thyroid gland that has slowed down.

The thyroid is a small, butterfly-shaped gland in the front of the neck. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), thyroid hormones control the way your body uses energy, so they affect nearly every organ in your body. When the gland doesn’t make enough, many of the body’s functions slow down. The condition is called hypothyroidism.

It is not rare. The NIDDK says nearly 5 out of 100 Americans ages 12 and older have hypothyroidism, though most cases are mild or have few obvious symptoms. Women are much more likely than men to develop it, and it is more common after age 60. The American Thyroid Association notes that hypothyroidism is very common in patients over 60 years of age and steadily increases with age.

Part of what makes it easy to miss is timing. The NIDDK says that because the condition develops slowly, you may not notice symptoms for months or even years. Here are six signs that often get written off as normal aging.

Tiredness that doesn’t lift. Fatigue is among the most common symptoms the NIDDK lists. The American Thyroid Association also includes sleepiness and fatigue among the signs. It is also one of the vaguest, which is why it so often gets chalked up to a busy week or a bad night’s sleep.

Weight gain without an obvious reason. Cleveland Clinic explains that hypothyroidism slows down your metabolism, which may make you gain weight unexpectedly. The NIDDK cautions that fatigue and weight gain are common and do not necessarily mean a thyroid problem.

Always feeling cold. Trouble tolerating cold appears on the NIDDK’s list of common symptoms. Someone who keeps nudging up the thermostat in a house where others are comfortable may notice this one first.

Dry skin and thinning hair. The NIDDK lists dry skin or dry, thinning hair as common symptoms. Cleveland Clinic describes the skin and hair changes as dry and coarse.

Memory slips. This may be the sign most likely to be dismissed. The American Thyroid Association says that in older patients, memory loss or a decrease in cognitive functioning, often attributed to advancing age, may be the only symptoms of hypothyroidism. Cleveland Clinic includes brain fog, described as forgetfulness or difficulty concentrating, among possible symptoms.

Constipation. The American Thyroid Association lists constipation among the signs of hypothyroidism and notes that in older patients the condition often shows up in subtle ways, sometimes looking like a problem of the bowel, heart or nervous system.

None of these signs proves anything on its own. The NIDDK says a hypothyroidism diagnosis can’t be based on symptoms alone because many of its symptoms are the same as those of other diseases. A blood test settles the question. The American Thyroid Association calls it the only way to know for sure.

Treatment is a daily medicine. When a test does confirm low thyroid, the NIDDK says the condition most likely can be completely controlled with thyroid hormone medicine taken as directed.

This article is for general information and is not medical advice. If any of these symptoms sound familiar, talk to your doctor about whether a thyroid blood test makes sense for you.