Hypothyroidism: Symptoms, Causes, Condition During Pregnancy, Consequences, Treatment and Diet

It occurs when the thyroid gland does not produce enough amounts of thyroid hormones.

Women, especially those over 60 years of age, are more likely to suffer from thyroid problems. Hypothyroidism alters the balance of hormonal and chemical reactions in the body.

This condition does not usually produce symptoms in its early stages and, if not treated early, can cause health problems, such as obesity, joint pain, infertility, and heart disease.

What are your symptoms?

The symptoms of Hypothyroidism are changing; everything depends on the severity of the hormonal deficiencies. However, any problem you have tends to develop slowly, often for several years.

At first, you may notice the symptoms of Hypothyroidism, such as increased fatigue and weight, or symptoms that can be attributed to age.

As the metabolism slows down, it can develop more apparent symptoms. Among these may include:

  • Weight gain.
  • Impairment of memory.
  • Fatigue.
  • Muscular weakness.
  • It is thinning of hair fibers.
  • Increased sensitivity to cold.
  • Constipation.
  • Dry Skin.
  • Depression.
  • Decreased heart rate
  • Swollen face.
  • High blood cholesterol level.
  • Muscle sensitivity, stiffness, and pain.
  • Pain, stiffness, or swelling in the joints.
  • Irregular menstrual periods.
  • Hoarseness

What are the causes of Hypothyroidism?

When the thyroid does not produce enough hormones, the balance of chemical reactions in the body is modified.


There may be several causes, including some autoimmune diseases.

Hypothyroidism occurs when the thyroid does not produce hormones in sufficient amounts for the body. This condition can be due to several factors, including:

Treatment for hyperthyroidism. People who produce too much thyroid hormone (hyperthyroidism) are often treated with radioactive iodine or antithyroid drugs to reduce and normalize their thyroid function.

However, treatment of hyperthyroidism can result in permanent Hypothyroidism in some cases.

Autoimmune disease . People who develop a particular inflammatory disorder, known as Hashimoto’s Thyroiditis, are the most common cause of Hypothyroidism.

Autoimmune disorders occur when the immune system produces antibodies that attack its tissues. Sometimes, this process involves the thyroid gland.

Radiation therapy . Radiation used to treat cancers of the head and neck can affect the thyroid gland and lead to Hypothyroidism.

Thyroid surgery . Eliminating the thyroid gland in its entirety or a large part of your thyroid gland can reduce or stop the production of hormones. In that case, you will have to take thyroid hormone for life.

Drugs . Several medications can contribute to Hypothyroidism. One of these medications is lithium, which is used to treat certain mental disorders.

If you are taking medication, consult your doctor about its effect on the thyroid gland.

Condition during pregnancy

Pregnant women with overt Hypothyroidism should receive replacement therapy with levothyroxine at the adjusted dose to achieve a TSH concentration within the specific reference range of the trimester.

Serum TSH levels should be evaluated every four weeks during the first half of pregnancy to adjust the dosage of levothyroxine to maintain TSH within the specific range of the trimester.

The serum TSH should be re-evaluated during the second half of pregnancy.

In women who are already taking levothyroxine, two additional doses per week of the current dose of levothyroxine, administered as an extra dose twice a week with several days of separation, can be started as soon as pregnancy is confirmed.

Hypothyroidism in pregnancy can produce a variety of obstetric complications. Even a mild illness can have adverse effects on the offspring.

The adverse effects of Hypothyroidism in pregnancy include the following:

  • Preeclampsia.
  • Anemia.
  • Postpartum hemorrhage.
  • Cardiac ventricular dysfunction.
  • Increased risk of spontaneous abortion
  • Low birth weight
  • Impairment of cognitive development in the fetus.
  • Fetal mortality
  • Despite the possibility of poor fetal outcomes, routine screening for thyroid dysfunction is not performed in the United States and remains a controversial issue.

A study that reviewed the records of pregnant women evaluated between June 2005 and May 2008 found that only 23% of these women underwent hypothyroidism tests.

The study also found a 15% prevalence of Hypothyroidism among pregnant women, a figure that is significantly higher than the 2-3% frequently cited in the oldest literature.

The increase in thyroid hormone dose requirements should be anticipated during pregnancy, especially in the first and second trimesters.

Studies have suggested that in pregnant women with Hypothyroidism, the dose of LT4 should be increased by 30% at confirmation of pregnancy and subsequently adjusted according to TSH levels.

In addition, iodine demands are higher with pregnancy and lactation.

Iodine requirements increase from approximately 150 μg / day in non-pregnant women to 240-290 μg / day during pregnancy and lactation.

The guidelines of the American Thyroid Association recommend that all pregnant and lactating women should ingest a minimum of 250 mg of iodine daily, optimally, in the form of potassium iodide, to ensure a constant delivery.

For pregnant women with previously diagnosed Hypothyroidism, serum TSH levels should be measured every 3-4 weeks during the first half of pregnancy and every 6-10 weeks after that.

The dose of LT4 should be adjusted to maintain serum TSH below 2.5 mIU / L.

TSH and free T4 levels should be measured 3 to 4 weeks after each dose adjustment.

Consequences of Hypothyroidism

Gastrointestinal problems: Hypothyroidism is a common cause of constipation. Constipation in Hypothyroidism may be the result of decreased motility of the intestines.

This can lead to intestinal obstruction or abnormal colon enlargement in some cases.

Hypothyroidism is also associated with a decrease in motility in the esophagus, which causes difficulty in swallowing, heartburn, indigestion, nausea, or vomiting.

Abdominal discomfort, flatulence, and bloating occur in those with bacterial growth of the small intestine secondary to poor digestion.

Depression and psychiatric disorders: panic disordersdepression, and changes in cognition are frequently associated with thyroid disorders.

Hypothyroidism is often misdiagnosed as depression.

A study published in 2002 suggests that thyroid function is essential for patients with bipolar disorder: “Our results suggest that almost three-quarters of patients with bipolar disorder have a thyroid profile that may be suboptimal for the antidepressant response.”

Cognitive impairment: patients with low thyroid function may suffer from delayed thinking, delayed processing of information, difficulty remembering names, etc.

Patients with subclinical Hypothyroidism show decreased working memory and reduced sensory and cognitive processing speed.

An evaluation of thyroid hormones and TSH can help prevent the misdiagnosis of depression.

Cardiovascular disease: Hypothyroidism and subclinical Hypothyroidism are associated with high blood cholesterol levels, increased blood pressure, and increased risk of cardiovascular disease.

Even those with subclinical Hypothyroidism were almost 3.4 times more likely to develop cardiovascular disease than those with healthy thyroid function.

High blood pressure: hypertension is relatively common among patients with Hypothyroidism.

In a 1983 study, 14.8% of patients with Hypothyroidism had high blood pressure, compared to 5.5% of patients with normal thyroid function.

“Hypothyroidism has been recognized as a cause of secondary hypertension. Previous studies have shown high blood pressure values. “

“It has been suggested that the increase in peripheral vascular resistance and low cardiac output is the possible relationship between hypothyroidism and diastolic hypertension.”

High cholesterol and atherosclerosis: “Evident Hypothyroidism is characterized by hypercholesterolemia and a marked increase in low-density lipoproteins (LDL) and apolipoprotein B.

“These changes accelerate atherosclerosis, which causes coronary artery disease. The risk of heart disease increases proportionally with the increase in TSH, even in subclinical Hypothyroidism.

Hypothyroidism caused by autoimmune reactions is associated with the rigidity of the blood vessels. The replacement of thyroid hormone can slow the progression of coronary heart disease by inhibiting the passage of the plaques.

Homocysteine: treating hypothyroid patients with thyroid hormone replacement may attenuate homocysteine ​​levels, an independent risk factor for cardiovascular disease.

“A strong inverse relationship between homocysteine ​​and free thyroid hormones confirms the effect of thyroid hormones on the metabolism of homocysteine.”

High C-reactive protein: overt and subclinical Hypothyroidism is associated with increased levels of low-grade inflammation, as indicated by elevated C-reactive protein (CRP).

A clinical study in 2003 observed that CRP values ​​increased with progressive thyroid insufficiency and suggested that it may count as an additional risk factor for the development of coronary disease in patients with Hypothyroidism.

Metabolic syndrome: In a study of more than 1500 subjects, the researchers found that those with metabolic syndrome had significantly higher TSH levels (i.e., lower thyroid hormone production) than healthy control subjects.

Subclinical Hypothyroidism also correlated with elevated triglyceride levels and increased blood pressure. A slight increase in TSH can put people at higher risk of metabolic syndrome.

Problems of the reproductive system: in women, Hypothyroidism is associated with menstrual irregularities and infertility. Proper treatment can restore a regular menstrual cycle and improve fertility.

Fatigue and weakness: The standard and well-known symptoms of Hypothyroidism, such as chills, weight gain, paraesthesia (tingling or tingling sensation in the skin), and cramping, are often absent in older patients compared to younger patients.

Fatigue and weakness are common in patients with Hypothyroidism.


The standard treatment for Hypothyroidism involves using the synthetic thyroid hormone levothyroxine. This medication replenishes hormone levels to adequate limits, reversing symptoms of Hypothyroidism.

After starting the oral treatment, you will notice that you feel less tired. These medications gradually reduce high cholesterol levels due to the disease and can also prevent any weight gain.

Treatment with levothyroxine is usually for life, but your doctor may want to periodically check your hormone levels because the dose you need may vary.

Thyroid hormone can be started at anticipated doses of complete replacement in young individuals who otherwise are healthy.

Clinical benefits begin in 3-5 days and level off after 4-6 weeks.

Achieving a TSH level within the reference range can take several months due to the delayed readaptation of the hypothalamic-pituitary axis.

In patients receiving treatment with LT4, changes in dosage should be made every 6-8 weeks until the patient’s TSH is in the target range.

In patients with central Hypothyroidism (i.e., pituitary or hypothalamic), T4 levels instead of TSH levels are used to guide the treatment.

In most cases, the free level of T4 must be maintained in the upper third of the reference range.

After dose stabilization, patients can be monitored with annual or semi-annual clinical evaluations and TSH monitoring.

Patients should be monitored for symptoms and signs of overtreatment, which include the following:

  • Tachycardia.
  • Palpitations
  • Atrial fibrillation
  • Nervousness.
  • Fatigue.
  • Headache.
  • Increase in excitability.
  • Insomnia.
  • Tremors
  • Possible angina.

The updated guidelines on Hypothyroidism published by the American Thyroid Association in 2014 maintain the recommendation of levothyroxine as the preparation of choice for Hypothyroidism.

If the dose requirements for levothyroxine are much higher than expected, consider evaluating gastrointestinal disorders such as Helicobacter pylori-related gastritis, atrophic gastritis, or celiac disease.

If such disorders are detected and treated effectively, re-evaluation of thyroid function and dosage of levothyroxine is recommended.

A reassessment of steady-state serum TSH should follow the initiation or suspension of estrogens and androgens since such medications may alter the requirement for levothyroxine.

The serum TSH must be re-evaluated after starting agents such as tyrosine kinase inhibitors that affect the metabolism of thyroxine or deiodination with triiodothyronine.

The control of serum TSH is advisable when initiating medications such as phenobarbital, phenytoin, carbamazepinerifampicin, and sertraline.

When deciding the initial dose of levothyroxine, the patient’s weight, the lean body mass, the pregnancy status, the etiology of the Hypothyroidism, the degree of TSH elevation, the age, and the general clinical context, including the presence of heart disease.

The objective of serum TSH appropriate for the clinical situation should also be considered.

Thyroid hormone therapy should be initiated as an initial complete replacement or partial replacement with gradual increases in the dose adjusted upward using serum TSH as the target.

Dose adjustments should be made with significant changes in body weight, aging, and pregnancy.

TSH evaluation should be done 4-6 weeks after any dose change.

The reference ranges of serum TSH levels are higher in older populations (e.g.,> 65 years), so more elevated serum TSH levels may be appropriate.

Diet for Hypothyroidism

There is no specific diet tested to treat everyone with Hypothyroidism. An individualized approach to nutrition is necessary.

Some clinical evidence has shown that the following diets have helped some people with Hypothyroidism:

  • Gluten-free diet
  • Diet without sugar.
  • Paleo diet.
  • Diet without grains.
  • Diet without dairy.
  • Low glycemic index diet.

Let’s take a closer look at some of these diets below:

Without gluten or grains:

Many people with Hypothyroidism also experience sensitivities to food, especially gluten.

There is no current research to support a gluten-free diet for all people with Hypothyroidism unless they also have celiac disease.

However, in a survey of 2232 people with Hypothyroidism, 76 percent of respondents believe they are sensitive to gluten.

The respondents mentioned constipation, diarrhea, cramps, bloating, nausea, reflux, gas, headaches, fatigue, and mental fog as symptoms of their reactions to gluten.

Of those surveyed, 88 percent of those who tried a gluten-free diet felt better.

Many people also reported improvements in digestion, mood, energy levels, and weight reduction.

Gluten-free diets eliminate all foods containing gluten, a protein found in wheat, barley, rye, and other grains.

Gluten is commonly found in pasta, bread, baked goods, beer, soups, and cereals.

The best way to do this is to focus on foods that do not contain gluten, such as vegetables, fruits, lean meats, seafood, beans, legumes, nuts, and eggs.

Diet without cereals:

A grain-free diet is very similar to gluten-free, except the grains are also out of bounds. These grains include:

  • Amaranth.
  • Quinoa.
  • Avena.
  • Alforfón.

However, there is little evidence that cutting grains are beneficial for health.

Cutting these grains can also eliminate fiber and other sources of essential nutrients, such as selenium, which are necessary for people with Hypothyroidism.


The Paleo diet tries to mimic the feeding patterns of our primitive ancestors, with an emphasis on whole, unprocessed foods.

Grains, dairy products, potatoes, beans, lentils, refined sugar, and refined oils are not allowed.

Free cage and grass meats are encouraged, as are vegetables, nuts (except peanuts), seeds, shellfish, and healthy fats, such as avocado and olive oil.

The Paleo Autoimmune Diet aims to decrease foods that can cause inflammation and damage the intestine.

Start with the basic principles of the Paleo diet, but also cut the solanaceous vegetables, such as tomatoes, eggs, nuts, and seeds.

Low IG diet:

A low glycemic index or a low GI diet is based on an index that measures how each food affects a person’s blood sugar levels.

Some people with type 2 diabetes use this diet; diet can also reduce the risk of heart disease and help some people lose weight.

Dense in nutrients:

A high-density nutrient diet plan may be the best option for people who do not want to focus on what foods to cut.

A diet rich in nutrients includes variety and focuses on whole foods with a selection of colorful fruits and vegetables, healthy fats, lean proteins, and fibrous carbohydrates. The foods include:

  • Green leafy vegetables, such as kale and spinach.
  • Fatty fish, including salmon.
  • Various colorful vegetables include Brussels sprouts, broccoli, carrots, beets, and red, yellow, and orange peppers.
  • Fruits, including berries, apples, and bananas.
  • Healthy fats, including avocado and nuts.
  • Lean proteins, including tofu, eggs, nuts, beans, and fish.
  • Fibrous foods, including beans and legumes.

These foods will leave less space for processed and refined sugar foods as the diet’s primary focus.

Anti-inflammatory spices such as turmeric, ginger, and garlic are also recommended.

Nutrients for Hypothyroidism:

Research suggests that certain nutrients also play a role in Hypothyroidism disease. These include:

Vitamin D:

Several studies have found a relationship between low vitamin D levels and Hypothyroidism. In 218 people with Hypothyroidism survey, 85 percent had insufficient vitamin D levels.

Anyone diagnosed with Hypothyroidism disease should test their vitamin D levels.

Vitamin D can be produced in the body during sun exposure or consumed through food or supplements.

As many adults now spend most of their days indoors, low vitamin D levels are becoming more common.

According to the National Institutes of Health, “approximately 5-30 minutes of sun exposure between 10 AM and 3 PM at least twice a week on the face, arms, legs or back without sunscreen usually lead to enough vitamin D. “

If constant exposure to the sun is not possible, it is good to take supplements, as very few foods contain adequate amounts of vitamin D.

The best dietary sources of vitamin D include:

  • Cod liver oil.
  • Swordfish.
  • Salmon.
  • Tuna.
  • Fortified orange juice.
  • Enriched milk
  • Sardines
  • Mushrooms.

Low levels of selenium are standard in many people with Hypothyroidism. Selenium is an essential trace mineral necessary for brain function, immunity, and fertility.

The most significant selenium found in the body is stored in the thyroid gland. Several studies have shown that selenium supplementation may benefit people with thyroid dysfunction.


The best food sources of selenium:

  • Brazil nuts.
  • Tuna.
  • Oysters.
  • Sardines
  • Langosta.
  • Liver.
  • Beef-fed grass.
  • Sunflower seeds
  • Eggs

Meals to avoid:

Each person is different, but some people with Hypothyroidism reported improved symptoms by avoiding:

  • Food with gluten.
  • Foods with refined or added sugar.
  • Processed foods.

Anyone thinking about starting a gluten-free diet should talk to their doctor, as they can help determine if a person has gluten sensitivity.


It is more important for a person to follow a well-balanced diet that works for their lifestyle than trying to label their eating habits.

People should concentrate on the whole, unprocessed foods and eat foods that grow on the ground, not foods in boxes or bags.

While a gluten-free diet or an autoimmune protocol can help relieve a person’s symptoms, it may not work for everyone.

People with Hypothyroidism should be willing to try different feeding styles until they find the one that makes them feel better.

They should also talk to a doctor or dietitian about ensuring they get all the essential nutrients.