Yes, an enlarged thyroid (goiter) can cause snoring, but usually only when it is large enough to press on the windpipe or extends down behind the breastbone. An underactive thyroid (hypothyroidism) is a more common link. It can cause swelling of the tongue and throat tissues, weight gain and weaker breathing control, all of which raise the risk of snoring and obstructive sleep apnea. Both problems are diagnosed with a simple exam, blood tests and, if needed, imaging and a sleep study.
Key Takeaways
- A goiter is any enlargement of the thyroid. Most are small and cause no breathing symptoms. Large or substernal goiters (extending into the chest) can narrow the airway.
- In one surgical series, 77% of snorers with substernal goiters reported less snoring after the goiter was removed. Sleep-study improvements were less consistent.
- Hypothyroidism is linked to sleep apnea through tongue enlargement, fluid-rich tissue in the upper airway, weight gain, muscle weakness and a blunted drive to breathe.
- Thyroid hormone treatment can reduce apnea in some people but not all. Many still need CPAP or another sleep apnea treatment.
- See a doctor promptly for neck swelling, trouble swallowing or breathing, hoarseness, or breathlessness when lying flat.
How the Thyroid Is Connected to Snoring
The thyroid is a butterfly-shaped gland in the front of the neck, wrapped around the windpipe (trachea) just below the voice box. It makes hormones that set the pace of your metabolism. Thyroid problems can affect breathing during sleep in two different ways.
1. A goiter that physically narrows the airway
According to the American Thyroid Association, a goiter is simply an abnormal enlargement of the thyroid. It can occur with normal, high or low hormone levels. In the US, common causes include Hashimoto's thyroiditis, Graves' disease and multinodular goiter. Worldwide, iodine deficiency is the leading cause.
Most goiters are small and never affect breathing. MedlinePlus notes that in rare cases an enlarged gland presses on nearby structures, causing breathing difficulty, cough, hoarseness or trouble swallowing. Two types are most likely to affect sleep:
- Large multinodular goiters that press on or displace the windpipe.
- Substernal (retrosternal) goiters that grow down behind the breastbone into the chest, where there is little room for the trachea to move aside. Lying flat can make the squeeze worse.
In a 2012 study of patients having surgery for substernal goiter, 59 of 77 snorers (76.6%) reported improved snoring after thyroidectomy. The authors concluded that goiter should be considered when sleep apnea is diagnosed. The objective evidence is mixed, though. A separate study of 24 patients with large goiters found that sleep apnea symptoms improved after surgery, but sleep-study breathing measures did not change significantly. A goiter can contribute to snoring, but it is rarely the only cause.
2. An underactive thyroid that changes the airway
Hypothyroidism is the better-established link with obstructive sleep apnea (OSA). Proposed mechanisms include:
- Tongue enlargement (macroglossia) and swelling of throat tissue from deposits of water-binding substances (myxedema)
- Weight gain, which adds tissue around the neck and airway
- Weaker upper-airway muscles (hypothyroid myopathy) that collapse more easily during sleep
- Reduced breathing drive, meaning the brain responds less strongly to low oxygen and high carbon dioxide
- An enlarged thyroid in some cases, for example in Hashimoto's thyroiditis
The NIDDK lists fatigue, weight gain, trouble tolerating cold, joint and muscle aches, dry skin or thinning hair, a slow heart rate and depression as typical hypothyroid symptoms. Many of these overlap with untreated sleep apnea, which is one reason the two are easy to confuse.
Goiter vs. Hypothyroidism: How They Compare
| Goiter (enlarged thyroid) | Hypothyroidism (underactive thyroid) | |
|---|---|---|
| How it affects snoring | Physical pressure on the windpipe (large or substernal goiters) | Tissue swelling, weight gain, weak airway muscles, lower breathing drive |
| Typical clues | Visible or felt neck swelling, tightness when swallowing, hoarseness, breathlessness lying flat | Tiredness, feeling cold, weight gain, dry skin, constipation, low mood |
| Key tests | Neck exam, thyroid blood tests, ultrasound, CT if it extends into the chest | Thyroid blood tests (TSH and free T4) |
| Treatment | Depends on cause. Monitoring, medication, radioactive iodine or surgery if it compresses the airway. | Daily levothyroxine. Sleep apnea treatment if apnea persists. |
| Does fixing it stop snoring? | Often improves snoring when compression was the cause. Apnea results vary. | Improves apnea in some people. Many still need CPAP or an oral appliance. |
Diagnosis: Finding Out Whether Your Thyroid Is Involved
- Physical exam. A doctor feels the thyroid while you swallow and checks for nodules or enlargement.
- Blood tests. Thyroid function tests, usually starting with TSH, check for over- or underactivity. The NIDDK notes that hypothyroidism can't be diagnosed from symptoms alone.
- Imaging. A thyroid ultrasound shows size and nodules. A CT scan can show whether a goiter extends into the chest and narrows the trachea.
- Sleep study. A home or in-lab sleep test shows whether you have sleep apnea and how severe it is (see how to test for sleep apnea).
Treatment Options
If you have hypothyroidism
Hypothyroidism is treated with levothyroxine, a daily thyroid hormone tablet, with blood levels rechecked after 6–8 weeks. Restoring normal hormone levels can reduce tongue and throat swelling and help with weight. Studies on whether it resolves sleep apnea are small and mixed. In some patients the apnea index falls a lot, and in others it does not. If you have both conditions, don't wait on thyroid treatment alone. Treating diagnosed sleep apnea with CPAP or another therapy protects your heart and brain in the meantime. A follow-up sleep study after your thyroid levels are stable can show whether you still need it.
If you have a goiter
Treatment depends on the cause and size: monitoring, thyroid hormone, antithyroid treatment or radioactive iodine for Graves' disease, or surgery. The American Thyroid Association notes that surgery may be recommended when a goiter grows large enough to constrict the airway.
For snoring in the meantime
- Sleep on your side or with your head raised (see best sleeping positions to stop snoring).
- Avoid alcohol and sedatives in the evening.
- Work toward a healthy weight (see will I stop snoring if I lose weight?).
- Track your snoring with a snoring app to see whether treatment is helping.
Anti-snoring mouthpieces and nasal aids treat snoring that starts in the mouth, jaw or nose. They can't relieve pressure from a goiter lower in the neck, so get a diagnosis first.
When to See a Doctor
See your doctor if you notice any swelling in the front of your neck, or if you snore and have symptoms of an underactive thyroid. Get prompt care if you have:
- Trouble swallowing, a feeling of food sticking, or a persistent cough
- Hoarseness or voice changes lasting more than a few weeks
- Shortness of breath, noisy breathing (stridor) or breathlessness when lying flat
- Breathing pauses during sleep, choking or gasping, or heavy daytime sleepiness (see warning signs of sleep apnea)
Severe difficulty breathing is an emergency. Call 911.
This article is for general information and is not a substitute for medical advice.
Frequently Asked Questions
Can an enlarged thyroid cause snoring?
Yes, but usually only when the goiter is large or extends behind the breastbone, where it can narrow the windpipe. Most small goiters don't affect breathing. If you have neck swelling and new snoring, see a doctor for an exam and possibly imaging.
Can a goiter cause sleep apnea?
Large and substernal goiters have been linked to obstructive sleep apnea, and removing them often improves snoring and symptoms. Sleep-study results after surgery are mixed, so a goiter is usually one contributing factor among several.
Does hypothyroidism cause snoring?
It can contribute. An underactive thyroid can enlarge the tongue, cause fluid-rich swelling in throat tissue, add weight, weaken airway muscles and blunt the drive to breathe. These changes make snoring and sleep apnea more likely.
Will treating my thyroid stop my snoring?
Sometimes. Thyroid hormone treatment improves sleep apnea in some people with hypothyroidism, and goiter surgery often reduces snoring when compression was the cause. Many people still have apnea afterward, so a follow-up sleep study is the best way to know.
What are the signs an enlarged thyroid is pressing on the airway?
Watch for a feeling of tightness or pressure in the neck, trouble swallowing, hoarseness, a persistent cough, noisy breathing, and breathlessness that is worse when lying flat or raising your arms. These need prompt medical evaluation.
Should people with sleep apnea get a thyroid test?
Ask your doctor, especially if you also have symptoms such as fatigue, weight gain, feeling cold or dry skin. A simple blood test can rule hypothyroidism in or out, and treating it may make sleep apnea easier to manage.
Sources
- American Thyroid Association — Goiter
- MedlinePlus — Goiter, simple
- NIDDK — Hypothyroidism (Underactive Thyroid)
- Stang MT, et al. Positional dyspnea and tracheal compression as indications for goiter resection. Arch Surg. 2012 (PubMed)
- Haddad L, et al. Impact of thyroidectomy on the control of obstructive sleep apnea syndrome in patients with large goiters. Sleep Breath. 2014 (PubMed)
- Sleep apnea and hypothyroidism: mechanisms and management (PubMed)
