Defects In Smell and Taste With Hypothyroidism

Moreover, the effect of increased TSH on the latency of smell cortex potentials PN1 and PN5 in the subjects with 2 forms of hypothyroidism was evaluated. The methods used in clinical practice for objective examination of the olfactory function are based on recording reflex reactions. The main problem in computer-based olfactometry that consists in averaging cortex potentials is the manner of stimulation 14, 19, 20. As obtained in our study, disturbances of latency response to cortical stimulation on the olfactory nerve and trigeminal probably are related to disturbances of the cortex not receptor. Studies of other authors using more sophisticated methods to stimulate the olfactory structures (such as pyridine and nitrobenzene) affirm opportunity for differentiation of sensory or cortical disorders 10, 29.

Genetics and Deoiodination in Hashimoto’s and Hypothyroidism

• The fact is we don’t know exactly why an altered sense of taste can be a symptom of a thyroid issue.
• This is all more understandable that in the majority of respondents olfactory functions on discrete scents of mint and anise were not disturbed, though we found also in all this cases delayed latencies of cortical potentials PN1  and  PN5.
• 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.
• Taste comes from both our taste buds and olfactory glands detecting chemicals in foods.
• The present studies revealed that patients with hypothyroidism score lower on olfactory tests and tests for bitter sensitivity compared to healthy controls, and that olfactory function and bitter sensitivity increase following 3 months of treatment with thyroid hormones.
• Our study included 31 controls and 28 untreated subclinical hypothyroid patients.

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.

Receptors, central olfactory and gustatory areas, high order cognitive systems are all targets of hypothyroidism. The currently investigated effects could be related to lesions at one or several levels. Using immunohistochemistry Dhong et al. 13 evaluated hypothyroidism-related changes at the level of the olfactory epithelium of adult rats and found a Propyl Thio-Urasil (PTU)-exposure related decrease in the maturation of olfactory receptor neurons.

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.

• 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.
• Tests for smell, taste and endocrine function of patients and controls were recorded before and after treatment.
• 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.

off your first Thyroid Test

Symptomatology is often unspecific; main complaints are fatigue, constipation, weight gain and cold intolerance 4. Increased rate of cognitive dysfunction in subclinical hypothyroidism was shown in elderly population 6. The most common diagnosis in subclinical hypothyroidism is Hashimoto Thyroiditis 2. If you suspect your thyroid may be the cause, start by getting your thyroid checked. To do this, you can order a complete thyroid blood panel to see if your thyroid hormones are standard, high, or low.

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.

• Higher TSH levels or presence of anti-thyroid peroxidase antibodies (Anti-TPO) increase the conversion risk 1.
• Julia Walker, RN, BSN, is a clinical nurse specializing in helping patients with thyroid disorders.
• However total receptor count and density, olfactory epithelium surface area and thickness were found not to differ in relation to exposition with PTU.
• This study indicates that taste and smell defects are common clinical abnormalities in primary hypothyroidism, and suggests that these defects may contribute to the anorexia and lack of interest in eating which are frequently observed.
• Median detection thresholds for both smell stimuli were also markedly elevated (hyposmia) before therapy.

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.

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.

Sometimes, people experience pain on their synthroid seaweed tongue or other unusual symptoms when eating, like changes in food textures and temperature. People frequently don’t bring it up to their health providers because it may seem obscure, or you think it may resolve with time. One of the most common thyroid conditions is hypothyroidism, where your thyroid cannot produce a sufficient amount of thyroid hormone. Subclinical hypothyroidism is defined as a situation in which serum levels of free thyroxin (fT4) are normal and serum thyroid-stimulating hormone (TSH) levels are elevated 1. Situations like recent levothyroxine adjustment which did not reach the steady state, recovery phase of severe illnesses, thyroiditis by different etiologies, external sources of TSH variance, presence of biochemically TSH mimicking markers were excluded from this definition 2. It was noted, however, that irrespective of the volume of inhaled stimulus fragrance, rapid olfactory fatigue was observed.

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.