When is Weight Gain a Health Concern?

If you’ve put on a few pounds over the winter, don’t panic. It’s totally normal to gain weight during the colder months.

It’s also normal for your body to change as you get older—it’s common to gain a pound a year from age 20 to age 40, said Kathleen Wyne, an endocrinologist at The Ohio State University Wexner Medical Center.

So when should weight gain be something to worry about? A rapid spike in weight can be a symptom of a larger health problem, like hypothyroidism. Here’s how to tell the difference between a few harmless pounds and a cause for concern.

Weight worth worrying about?

Weight Gain Rewire PBS
It’s normal for your weight to fluctuate. But you can always talk to your doctor about weight gain or loss if you’re concerned.

Hypothyroidism occurs when your thyroid gland does not make enough thyroid hormone to maintain your metabolism, Wyne explained. In other words, when your thyroid gland is not working properly.

In the U.S., hypothyroidism is most commonly due to an autoimmune thyroid disease, typically referred to as Hashimoto’s Thyroiditis or just Hashimoto’s, and affects about 1 to 2 percent of adults, she said. It is also more common in women than men.

So what are the best ways to tell if weight gain is normal, or might be a sign of a serious health issue like thyroid disease?

1. Consider how rapid your weight gain is

“Weight gain that may be due to a medical condition would be a rapid weight gain, such as over six months, with no change in activity or food intake,” Wyne said. Think about a 30- to 50-pound weight gain over that time frame—but, Wyne noted, this is actually quite a rare symptom of hypothyroidism. Other symptoms would likely occur first, such as fatigue or hair loss.

“We all have ups and downs in our weight,” said Lewis Blevins, medical director at the California Center for Pituitary Disorders at the University of California San Francisco. But when anything out of the ordinary is happening, such as a 50 percent increase in body weight over a short period of time, you should get evaluated, he said.

2. Consider the weight gain patterns of your family

Another thing to keep in mind is how and when family members, such as parents and siblings, gain weight, Blevins said. If most of your direct relatives put on a certain amount of weight when they hit their 30s, for example, that weight gain may be more related to your genetics than an underlying disorder.

Still, he emphasized you should visit a doctor if you’re uncomfortable about your weight gain. Your doctor will take other symptoms into account and try to catch any underlying health issues.

3. Take a look at some of your other symptoms

Hypothyroidism can be slow to develop, Wyne said. However, earlier symptoms—which may be more likely for people in their 20s and 30s—include fatigue, hair thinning and hair loss, dry skin, cold intolerance, depression and irregular periods, she said.

Symptoms that occur with more severe hypothyroidism can include difficulty concentrating, memory impairment, weakness, joint aches and weight gain, Wyne explained.

4. Check if you fall into any higher-risk group

Hypothyroidism is more common in certain groups, such as women or people with type 1 diabetes, Down syndrome or a family history of thyroid disease, Wyne noted.

Overall, “it’s important to recognize that your body is going through changes in your 20s, and you’re settling into your adult metabolism,” Blevins said. But if your weight gain is unusual for your body and your family history, then you should talk to a doctor, he said.

Stephanie M. Bucklin

Stephanie Bucklin is a freelance writer whose work has been published by New York Magazine, TODAY.com, Vice and other outlets. She has also written a children’s book, “Jack Death,” published in 2016 under a pen name. She graduated from Harvard with a degree in the history of science.