10 Hidden Health Dangers of a “Normal” Thyroid
If you notice any of these subtle symptoms but your thyroid levels come back normal, ask your doctor about subclinical hypothyroidism.
What is subclinical hypothyroidism?
You’ve heard of an overactive (hyper) and underactive (hypo) thyroid—when levels of TSH (thyroid stimulating hormone) and T4 (thyroxine) register well beyond the normal range. But your thyroid still may be malfunctioning, even if the levels look normal. Subclinical hypothyroidism (SCH) affects between 4 and 15 percent of the population and refers to having a slightly underactive thyroid; it’s distinguished by lab reports that show TSH levels above 4 but below 10 mlU/L, while T4 levels remain normal. “It’s called subclinical because many people with these findings do not have the typical symptoms one would expect to find in a patient with clinical hypothyroidism,” says Christian Nasr, MD, medical director of the Thyroid Center at Cleveland Clinic in Ohio. (These are clearer signs you might have a typical thyroid problem.)
Is it treated the same as full-blown hypothyroidism?
Experts are still split on the right way to treat subclinical hypothyroidism. “All medical societies agree that clinical hypothyroidism should be treated with thyroid hormone; however treating individuals with SCH the same way does not always improve the outcome,” he says.
It may be linked to type 2 diabetes
Those with prediabetes, a precursor to type 2 diabetes where blood sugar is higher than normal, and SCH may be at increased risk for type 2 diabetes. A large study carried out by researchers at Erasmus Medical Center in the Netherlands found that having a slightly underactive thyroid in addition to prediabetes increased a person’s risk of developing type 2 diabetes by 13 percent. These signs of type 2 diabetes can be easy to miss.
It may affect your heart and metabolism
More research is needed to state a definitive link, but “SCH could be associated with heart issues or metabolic disorders. Some studies are more clear-cut than others,” says Dr. Nasr. Find out the metabolism myths you can safely ignore.
It appears to impact your brain
Italian researchers analyzed 13 studies and found that people with SCH who were younger than age 75 had a 56 percent increased risk of impaired cognitive function and 81 percent increased risk of dementia. The reason may be because the longer your thyroid is underactive, even slightly, the more the thyroid gland (butterfly-shaped and located in the neck) is stimulated to release more and more hormones. This could lead to an enlarged thyroid (called a goiter) that could lead to cognitive issues like brain fog, forgetfulness, or depression.
It could affect your fertility
A study in the Journal of Pregnancy found that the women with SCH collectively had more trouble getting pregnant and birthed fewer children than those without. Low hormone levels can affect ovulation, which makes it harder to get pregnant. These are other silent signs of infertility.
You may feel fatigued
Some people with SCH may feel low energy, says Dr. Nasr. This means you feel more tired than usual doing regular activities, for no reason at all (you’re not sick or you haven’t changed your routine.) These are the best foods for a quick energy boost.
You might notice weight gain
Mysterious weight gain could be a sneaky sign of subclinical hypothyroidism. Unbalanced hormones can slow your metabolism, causing the pounds to gradually pile up, even when you haven’t changed your exercise or eating habits. These are the worst habits for belly fat.
You could feel cold all the time
If you can no longer tolerate cold weather or you feel cold all the time regardless of the weather, it could be a sign of a slightly underactive thyroid.
You may suffer from constipation
Thyroid hormones help regulate the digestive system, so too little coursing through your body could trigger constipation. If this is a problem for you, try these constipation cures.