Hypothyroidism is associated with prolonged COVID-19-induced anosmia: a case-control study

Peripheral neuropathy may occur particularly in the course of severe and persistent untreated hypothyroidism. Although the relationship between hypothyroidism and peripheral neuropathy is not entirely understood, it is known that hypothyroidism may cause fluid retention in the tissues and thus exert pressure on peripheral nerves 1–3. Changes include loss, decreased, increased or unpleasant changes in smell or taste. Some of these changes are a result of the ingredients in the drug, but most are due to the way the drug changes nerve synthroid fogginess sensation, chemicals or enzymes in the body. It could take months or years for a taste or smell disorder to develop from a drug, making it sometimes difficult to diagnose.

• Despite its small size, the thyroid plays a significant role in how your body functions.
• Implementing this method in diseases of the upper respiratory tract as a complementary method, for instance, in injuries of the craniofacial skeleton and surgical operations of the nasopharyngeal tumors, has already become quite common 5–7, 26, 27.
• Study designed in prospective cross-sectional fashion and approved by the Clinical Research Ethics Committee of Haydarpasa Training Hospital (HNEAH-KAEK 2013/ KK/117).
• Likely, your ability to taste your food is also reduced until your nasal congestion resolves.

The growing trend (visible in Figures 3–5) between TSH and latencies for the analyzed potentials proves to be a statistically significant relationship for PN1 at mint and anise stimulation (Figures 3 and 4) as well as for PN5 at mint stimulation (Figure 5). If you have changes in smell or taste that make it hard for you to take a drug, do not stop on your own. Your provider may be able to change the drug for you or suggest methods to improve your sense of taste or smell. Prevalence in adults was found in 4.3% of the U.S. population in National Health and Nutrition Examination Survey III 3 and ranged between 4–20% 4 in different studies.

Defects of taste and smell in patients with hypothyroidism

This range of applied speed of stimulus provides optimal recording cortical olfactory response. For speeds less than 5 mL/s single questionable entries for the control group were obtained, whereas at speeds greater than 50 mL/sec single false responses from the trigeminal nerve endings during the anise oil examination were registered. It can be suggested that they were caused by nonspecific mechanical or thermal stimulants. Taste and smell functions were measured in 18 unselected patients with untreated primary hypothyroidism, and in 15 of the 18 patients after treatment with thyroid hormones. Before treatment, 9 of the 18 patients (50 per cent) were aware of some alteration in their sense of taste, and 7 of the 18 patients (39 per cent) were aware of some alteration in their sense of smell.

She believes managing chronic illnesses requires a balance of medical interventions and lifestyle adjustments. Her background includes caring for patients in women’s health, critical care, pediatrics, allergy, and immunology. If you are on medication and suspect it has altered your sense of taste or smell, consider verifying with your thyroid doctor that you are on the correct dose first and then ask your doctor if they think the medication is the culprit. Living with an altered sense of taste and smell is doable, but it is not desirable, and it is not something you have to live with for the rest of your life. Therefore, people who struggle with the loss of smell often also have difficulty tasting their food and vice versa. Figures 3–5 show correlations between the parameters (TSH versus latency) under analysis for all the three study groups of subjects.

What is the thyroid connection to the sense of smell?

Therefore, the number of olfactory stimuli for an averaged response was limited to 10 repetitions in our tests. Older people who take more drugs are at highest risk for changes in taste or smell because they take more types of drugs, and drugs may interact with each other to cause these changes. These changes can be unpleasant and affect quality of life, but the main problem is that they may stop people from taking drugs that they need.

How Long After Starting Thyroid Medication to Lose Weight?

• A considerable difficulty seems to be how to ensure repeatable application of olfactory impulses.
• Most importantly, these deficits can be remedied on average within 3 months with adequate treatment.
• When food doesn’t taste right, it can alter your appetite and change your eating habits.
• Different studies revealed that hypothyroidism has effects at multiple points of the gustatory and olfactory perceptual pathways.
• Therefore, the number of olfactory stimuli for an averaged response was limited to 10 repetitions in our tests.

There have been introduced, however, the so-called impulse olfactometers in which it is possible to control parameters of the stimulus 19, 21, 22, yet another difficulty seems to be elimination of simultaneous irritation of other afferent endings 23. Study designed in prospective cross-sectional fashion and approved by the Clinical Research Ethics Committee of Haydarpasa Training Hospital (HNEAH-KAEK 2013/ KK/117). All subjects gave written informed consent and the institutional ethical committee approved the study protocol.

The most common cause of hypothyroidism is an autoimmune disease called Hashimoto’s thyroiditis, where chronic inflammation makes the thyroid unable to produce thyroid hormones. Sometimes, hypothyroidism may be due to a problem between the thyroid and thepituitary, a tiny gland in your brain that regulates hormones in your body. Despite its small size, the thyroid plays a significant role in how your body functions. From regulating your heart rate and metabolism to influencing your fertility and blood pressure, optimal thyroid functioning is vital for your overall health and wellbeing. Indeed, a poorly functioning thyroid can cause a slew of symptoms, many of which may seem bizarre, such as a decrease in your ability to taste and smell. The objective test method for mint and anise fragrance stimulation that has been used in our center for several years providing us with wide clinical experience appears to comply with the requirements of an objective investigation.

Verify your thyroid medication is correct

The olfactory system is expected to be influenced as a part of neurologic system. Hovewer, Brosvic 17 et al. investigated behavioral differences in hypothyroid and control rats; they found no significant differences in odor detection performance between the two groups. Difference significance test in latencies of recorded cortical responses PN1 and PN5 between the groups of patients with overt clinical versus subclinical hypothyroidism as well as between the control group versus subclinical hypothyroidism group.

Table 2. Olfactory and Taste results of Patients (before and after treatment) and Controls.

Distoritions of tase (dysgeusia) and smell (dysosmia) were frequent complaints among the untreated patients; dysgeusia was observed by 7 patients (39 per cent) and dysosmia by 3 patients (17 per cent). Before treatment, decreased taste acuity (hypogeusia) for at least one stimulus was observed in 14 of the patients (83 per cent); the most common abnormalities were in the detection and recognition of bitter stimuli. Median detection thresholds for both smell stimuli were also markedly elevated (hyposmia) before therapy. Treatment with throid hormones largely reversed both the taste and smell defects. In one patient, taste and smell abnormalities were completely corrected after 16 days of treatment with thyroxine.

Your brain uses messages from both your tastebuds and your olfactory glands to determine your perceptions of smell and taste. Application of the olfactory stimulus is synchronized with the inspiration phase of the subject in our study. Automatically, using the vacuum sensor that reacts to the onset of each inspiration, the olfactory applicator starts the device for recording the averaged evoked responses. Methods of recording the potentials of smell used by us turned out to be accurate, and problems with stimulation of the olfactory organ were overcome.