Thyroiditis: Symptoms, Causes & Treatment Options

The thyroid is a small butterfly-shaped gland in your neck that quietly regulates how your body uses energy throughout the day. It plays a role in metabolism, heart rate, body temperature, mood, and concentration. Most people are unaware of its presence because it works steadily in the background. However, when this gland becomes inflamed, the body’s balance can begin to change. Energy levels may fluctuate, weight changes may feel unexpected, and sleep and mood may no longer feel consistent.

In this blog, we explain thyroiditis and how it affects the body, the phases it goes through, common types, symptoms, causes, diagnosis, and treatment options, which help you to recognise changes early and make informed decisions about your health.

What Is Thyroiditis?

Thyroiditis is a medical condition in which the thyroid gland becomes inflamed, affecting its ability to function normally. This inflammation disrupts the controlled production and release of thyroid hormones. Instead of maintaining a steady balance, the gland may release an excessive amount of hormones into the bloodstream or, at times, struggle to produce enough to meet the body’s needs.

The condition often develops gradually rather than causing immediate thyroid failure. In many cases, hormones that are already stored within the gland leak into the bloodstream first, leading to a temporary rise in hormone levels. As these stored hormones are depleted, the thyroid’s activity may slow down, resulting in lower hormone levels for a period of time before balance is restored or further treatment is required.

Different Phases of Thyroiditis

Thyroiditis often moves through distinct phases. Not everyone experiences all of them, but understanding these stages helps explain why symptoms change over time.

Thyrotoxic Phase

This is usually the first stage and happens when the inflamed thyroid releases excess hormone into the bloodstream. It often lasts one to three months and causes the metabolism to speed up. You may notice a fast heartbeat, weight loss without trying, anxiety, or shakiness. In this phase, the thyroid is not overproducing hormones but releasing those already stored.

Hypothyroid Phase

As hormone stores become depleted, the damaged thyroid may not be able to produce enough new hormone. This phase can last several months and often brings weight gain, sensitivity to cold, low energy, and mood changes. For some people, this phase is temporary, while for others it may become long-term.

Euthyroid Phase

This is the recovery phase where thyroid hormone levels return to normal. The inflammation subsides, and the gland resumes functioning in a balanced manner again. Some people naturally reach this phase, while others may require ongoing treatment if the thyroid has not fully recovered.

Types of Thyroiditis

Doctors classify thyroiditis into different types based on what triggers the inflammation and how long it lasts. Identifying the type helps guide treatment and gives a clearer idea of what to expect over time.

Hashimoto’s Thyroiditis

This is the most common form and is caused by an autoimmune response where the immune system mistakenly attacks the thyroid. It develops slowly over the years and usually does not cause pain. Over time, it often leads to permanent hypothyroidism, meaning many people need lifelong thyroid hormone medication to maintain normal body function.

Subacute Thyroiditis

This type is often painful and is usually linked to a recent viral infection such as the flu or mumps. Pain may be felt in the front of the neck and can spread to the jaw or ears. It typically follows a short phase of high hormone levels, followed by low levels and usually resolves on its own within a few months.

Postpartum Thyroiditis

Postpartum thyroiditis affects some women within a year after childbirth. It occurs when the immune system becomes more active again after pregnancy and affects the thyroid. Early symptoms can be mild and easily overlooked. Most women recover fully, but having it once increases the risk of future thyroid problems.

Silent Thyroiditis

Also called painless thyroiditis, this autoimmune condition causes inflammation without pain. It can affect both men and women and follows the same temporary rise and fall in hormone levels. It often settles on its own, though regular monitoring is important to ensure recovery.

Infectious Thyroiditis

This is a rare form caused by a bacterial infection. It usually comes with fever, severe neck pain, and signs of illness. Prompt treatment with antibiotics is required to clear the infection and prevent complications.

Drug-induced Thyroiditis

Certain medications can irritate or damage the thyroid as a side effect. Drugs such as lithium, amiodarone, and interferons are known to trigger this condition. In many cases, thyroid function improves once the medication is adjusted or stopped, with careful medical supervision.

What Are The Symptoms of Thyroiditis?

The symptoms you feel depend heavily on which phase of the illness you are in and how severe the inflammation is. It can be confusing because the signs of high and low thyroid levels are almost opposites.

Symptoms of Excess Hormone

When the thyroid is leaking hormones during the thyrotoxic phase, your body’s engine is running too fast. You might experience:

• A rapid or pounding heartbeat (palpitations)
• Feeling nervous, anxious, or irritable for no clear reason
• Trembling hands or muscle weakness
• Trouble falling asleep or staying asleep
• Increased sweating and intolerance to heat
• Unintended weight loss despite a normal appetite​

Symptoms of Low Hormone

When hormone levels drop in the hypothyroid phase, everything slows down. Common signs include:

• Extreme fatigue and sluggishness
• Unexpected weight gain
• Constipation and slow digestion
• Dry, pale skin and brittle hair
• Puffy face or eyes
• Feeling cold all the time
• Muscle aches and stiffness

Causes and Risk Factors for Thyroiditis

Thyroiditis usually develops due to a combination of factors rather than a single cause. Genetics, infections, lifestyle habits, and environmental exposure can all affect the immune system and trigger inflammation of the thyroid.

Environmental and Viral Triggers

Certain viral illnesses are closely linked to thyroid inflammation, particularly painful types of thyroiditis. Infections like the flu or common cold can overstimulate the immune response, which may then affect the thyroid. In some cases, radiation exposure from medical treatments or environmental sources can damage thyroid tissue and trigger inflammation.

Genetic and Autoimmune Influence

A family history of thyroid or autoimmune disorders increases the likelihood of developing thyroiditis. In autoimmune forms, the immune system mistakenly identifies thyroid tissue as a threat and produces antibodies against it. This ongoing immune activity can gradually interfere with normal thyroid function.

Diet and Lifestyle Factors

Nutrition and daily habits also play a role in thyroid health. While iodine is necessary for hormone production, excessive intake through supplements or certain foods can disrupt thyroid balance in susceptible individuals. High levels of long-term stress may not directly cause thyroiditis, but they can strain the immune system and increase the risk of symptom flare-ups.

Key Risk Factors

• Age: While it can happen at any age, it is most common in middle-aged adults, typically between 30 and 50 years old.​
• Gender: Women are significantly more likely to develop thyroid issues than men. This is partly due to hormonal fluctuations during pregnancy and menopause.​
• Geographic Location: Living in an area with very high or very low iodine in the diet can increase risk.​
• Underlying Conditions: Having other autoimmune diseases like type 1 diabetes, rheumatoid arthritis, or lupus increases the chances of developing autoimmune thyroiditis.​

How Is Thyroiditis Diagnosed?

Because the symptoms of thyroiditis often overlap with many other health conditions, doctors use a combination of tests to understand what is happening in the thyroid and how active the inflammation is. Each test adds one piece to the overall picture.

Thyroid Function Tests

This is the most common starting point. A blood test measures Thyroid Stimulating Hormone (TSH) along with T3 and T4 levels. These values show whether the thyroid is releasing too much hormone, too little, or staying within the normal range. The pattern of these results also helps doctors identify which phase of thyroiditis you may be in

Thyroid Ultrasound

A thyroid ultrasound is a painless scan that uses sound waves to create images of the gland. It allows doctors to check the size of the thyroid, look for any lumps, and assess whether the tissue appears inflamed. Changes in blood flow seen on the scan can also support a diagnosis of thyroiditis.

Thyroid Antibody Tests

These blood tests look for antibodies that mistakenly attack the thyroid, such as TPO antibodies. When these antibodies are present, it strongly suggests an autoimmune cause like Hashimoto’s or postpartum thyroiditis.

ESR Test

The erythrocyte sedimentation rate, or ESR, is a simple blood test that shows how much inflammation is present in the body. In painful types of thyroiditis, this number is often quite high, reflecting active inflammation.

CRP Test

C-reactive protein is another marker of inflammation measured through blood testing. Raised CRP levels support the presence of ongoing inflammation and are especially helpful in confirming painful thyroid conditions

Radioactive Iodine Uptake Test

This test measures how much iodine the thyroid absorbs from the bloodstream. A healthy thyroid uses iodine to make hormones. In thyroiditis, the inflamed gland absorbs very little iodine, resulting in low uptake. This helps doctors distinguish thyroiditis from other conditions like Graves’ disease, where iodine uptake is high.

How Is Thyroiditis Treated?

Treatment for thyroiditis focuses on easing symptoms and bringing hormone levels back to normal. The exact approach depends on the type of thyroiditis and whether hormone levels are high or low at that time.

Beta Blockers

During the phase when hormone levels are high, beta blockers are often used to control symptoms like a fast heartbeat, tremors, and anxiety. They do not treat the thyroid itself, but help you feel more comfortable while levels settle on their own

Anti-Inflammatory Medicines

For painful types such as subacute thyroiditis, pain relief is important. Common pain relievers like ibuprofen or aspirin are usually enough to reduce neck pain and fever.

Corticosteroids

If pain and swelling are severe and do not improve with basic pain medicines, stronger anti-inflammatory drugs like prednisone may be prescribed. These help calm inflammation quickly and are used for a short period.

Hormone Replacement Therapy

If thyroid hormone levels drop too low or if there is permanent damage, synthetic thyroid hormone may be needed. This daily medicine replaces what the body cannot make and helps restore normal energy and metabolism.

Antibiotics

In rare cases where thyroiditis is caused by a bacterial infection, antibiotics are required. Treating the infection helps resolve the inflammation and prevent complications.

Surgery

Surgery is uncommon but may be considered if the thyroid becomes very enlarged, causes breathing or swallowing problems, or if there is concern about cancer.

Can Thyroiditis Be Prevented?

While you can't always prevent autoimmune conditions, there are steps you can take to lower your risk of developing thyroid issues related to infections or lifestyle factors.

• Vaccinations: Vaccines reduce the risk of viral infections that may trigger thyroid inflammation.
• Hygiene Practices: Good hygiene lowers the risk of bacterial infections that could affect the thyroid.
• Dietary Modifications: Balanced iodine intake supports thyroid health. Avoiding extremes is important.
• Lifestyle Changes: Managing stress, following medical advice, and monitoring thyroid health help reduce complications.

Wrapping Up

Thyroiditis is a condition that develops gradually, with symptoms and hormone levels changing over time. What may begin with mild or easily ignored signs can turn into a long-term health issue if left untreated. The good news is that with early diagnosis and the right treatment, many people either recover fully or can manage the condition effectively and maintain a good quality of life.

Managing thyroiditis often involves regular blood tests, specialist consultations, and, in some cases, long-term medication, making financial planning an important part of care. Niva Bupa’s NRI health insurance plans are designed to support this journey by offering access to comprehensive diagnostic tests, expert medical care, and coverage for ongoing treatment in India. With dependable health cover in place, NRIs and their families can reduce financial stress, ensure continuity of care, and focus on managing their health today while staying confidently prepared for the future.

People Also Ask

Can thyroiditis affect fertility?

Yes. Hormone imbalance can affect ovulation and menstrual cycles. Once thyroid levels are treated and stabilised, fertility usually improves.

Is thyroiditis more common after infections?

Some types appear after viral illnesses. The immune response can trigger temporary inflammation of the thyroid.

Can thyroiditis come back after recovery?

Yes. Certain types, like postpartum or autoimmune thyroiditis, can appear again, especially during periods of immune or hormonal change.

Does thyroiditis always require medication?

No. Mild cases may only need monitoring. Medication is prescribed when symptoms are strong or hormone levels drop too low.