Practice Guidelines

Treatment of Subclinical Hypothyroidism: BMJ Rapid Recommendation


Am Fam Physician. 2020 Sep 1;102(5):316-317.

Author disclosure: No relevant financial affiliations.

Key Points for Practice

• Thyroid hormones do not improve quality of life or thyroid-related symptoms in patients with subclinical hypothyroidism.

• In older patients, treatment of subclinical hypothyroidism does not improve muscle strength or cognitive function, but could increase mortality.

• In patients who are pregnant and in those with a TSH level greater than 20 mIU per L, severe symptoms, or age 30 years or younger, the benefit of subclinical hypothyroidism treatment is unknown.

From the AFP Editors

Subclinical hypothyroidism is a state of contradiction, with an elevated thyroid-stimulating hormone (TSH) level suggesting hypothyroidism but a normal free thyroxine level. Symptoms that suggest hypothyroidism may or may not be present. Treatment of subclinical hypothyroidism has long been controversial because of normal increases in TSH with age, variability between TSH measurements, and concerns for harm from treatment.

Previous guidelines suggested that levothyroxine treatment may be appropriate with hypothyroid symptoms or a TSH level exceeding 10 mIU per L based on limited evidence. A recent large trial in older adults suggests that treatment shows no benefit in many areas and possible harm. The BMJ/MAGIC Group sought to determine whether treatment of subclinical hypothyroidism increases quality of life measures, improves symptoms, or induces harm.

People 65 Years and Older

Studies of subclinical hypothyroidism primarily include older people. Substantial evidence demonstrates that levothyroxine is not beneficial for patients 65 years and older. Symptoms suggesting hypothyroidism, such as fatigue and depression, are not improved with supplementation more than with placebo. Quality of life and body mass index are unchanged. Muscle strength and cognitive function are not enhanced. Harms such as cardiovascular events and mortality are not more frequent, although data suggest that larger studies may demonstrate these risks. With no benefit and concern for harm,

Author disclosure: No relevant financial affiliations.

Coverage of guidelines from other organizations does not imply endorsement by AFP or the AAFP.

This series is coordinated by Michael J. Arnold, MD, contributing editor.

A collection of Practice Guidelines published in AFP is available at



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