The thyroid gland is a butterfly-shaped gland at the front of your neck. Thyroiditis is the swelling of this gland and causes either high or low levels of thyroid hormones in the blood.
There are different kinds of thyroiditis, but Hashimoto's thyroiditis is the primary cause of hypothyroidism (when levels of thyroid hormone are too low).
Hashimoto's thyroiditis is an autoimmune condition in which the body's immune system attacks and damages the thyroid gland cells. Initially, the damage can cause the thyroid gland to leak thyroid hormone. This leakage can lead to excess thyroid hormone in the blood (hyperthyroidism).
However, with time, the cell damage causes an underactive thyroid.
When you suffer from Hashimoto's thyroiditis:
Your immune system releases antibodies that attack the thyroid gland
Lots of white blood cells build up in the thyroid gland
The thyroid gland suffers damage and is unable to make enough thyroid hormones
The condition is most common in middle-aged women.¹ However, it can occur at any age and can affect men and children too.
Hashimoto's thyroiditis is sometimes referred to as chronic lymphocytic thyroiditis or autoimmune thyroiditis.
We make it easy for you to participate in a clinical trial for Hashimoto's disease, and get access to the latest treatments not yet widely available - and be a part of finding a cure.
The thyroid gland is a butterfly-shaped endocrine gland at the base of the neck. The gland releases thyroid hormones that control how your body regulates metabolic functions, such as:
An underactive thyroid gland results in too little thyroid hormone — a condition known as hypothyroidism. When the thyroid gland is overactive, it produces too much thyroid hormone (hyperthyroidism).
Hashimoto's thyroiditis gradually decreases the function of the thyroid gland, resulting in hypothyroidism. The disease mostly runs in families and impairs the ability of the thyroid gland to produce thyroid hormone.
The number of people in the US with Hashimoto's thyroiditis is unknown. However, the disorder is the leading cause of hypothyroidism, affecting 5% of Americans aged 12 and above.²
Women are four to ten times³ more likely than men to develop Hashimoto's disease. While teenagers and young women can also develop the disorder, Hashimoto's thyroiditis is more prevalent in women 30–50 years old.
The chances of developing Hashimoto's disease increase when you or your family have a history of autoimmune diseases such as:
Type 1 diabetes: A disorder of blood glucose rising too high
Rheumatoid arthritis: A condition of joint inflammation and deformity
Celiac disease: A condition that damages the small intestine
Lupus: A long-term disease that affects many parts of the body
Sjögren's syndrome: A condition that dries the mouth and eyes
Hashimoto's thyroiditis doesn't have its own set of distinctive symptoms, and the disorder usually progresses slowly over many years. People suffering from the disorder may lack symptoms early on, even if their blood test shows the presence of thyroid peroxidase (TPO). This enzyme is commonly in the blood if levels of thyroid hormone are too low.
Hypothyroidism can cause symptoms such as:
When Hashimoto's thyroiditis attacks thyroid tissue, the gland starts producing insufficient levels of thyroid hormone. A low concentration of thyroid hormone in the blood may cause extreme exhaustion that can interfere with your daily life.
The low level of thyroid hormone slows the body's metabolism, causing problems in regulating demands on physical energy.
You should confirm that a low level of thyroid hormones is the cause of your exhaustion. Don’t just assume that this is the cause of your fatigue.
Cold fingers and toes are possible signs of thyroid damage. A reduced level of thyroid hormone lowers body temperature due to a slower metabolism. You might start feeling cold even when the external environment is warm.
However, cold hands and feet aren't exclusive to Hashimoto's thyroiditis. This can be a symptom of other conditions such as impaired circulation. Consult with your doctor to confirm that Hashimoto's disease is causing you to be more sensitive to cold.
When someone has Hashimoto's thyroiditis, they may continue to gain weight even when exercising and eating a healthy diet.
This is because the thyroid gland is producing less of its hormones, so your body can’t burn off calories as quickly. Much of the weight gain is fluid build-up due to the effects of an underactive thyroid on your kidney function.
The more severe the damage to your thyroid, the more weight you're likely to gain.
Thyroid hormones regulate nearly all systems in the body, including digestion. When thyroid hormone levels drop, the digestion process slows down and causes constipation.
Symptoms of constipation include:
Less frequent bowel movements
Painful bowel movements
Dry, hard stools
Feeling that you haven't emptied your bowels
Research shows that 60% of people⁴ with thyroid disorders have depression.
Low levels of thyroid hormone can negatively affect your energy levels, physical strength, and brain functioning. These symptoms can lead to people with Hashimoto’s disease feeling depressed.
Low levels of thyroid hormone can cause exercise intolerance. When your blood has a low concentration of thyroid hormone, you lack the cardiovascular support to be able to do much exercise.
If you have Hashimoto’s disease, you may find you have insufficient blood flow, which limits your exercise capacity because of the slow delivery of oxygen.
Thyroid hormones regulate skin cells. Since these cells have a rapid turnover and a short lifespan, your skin will be sensitive to low thyroid levels.
Skin dryness that doesn't stem from skin allergies or new products could be a sign of Hashimoto's thyroiditis.
Some people with Hashimoto's thyroiditis show signs of muscle problems such as aches and stiffness, especially in the hips and shoulders.
Irregular periods⁵ can also be a sign of Hashimoto's thyroiditis.
The condition affects the reproductive hormones which can cause menstrual cycle changes.
Low levels of thyroid hormone slow down the heart's function. For people with Hashimoto's thyroiditis, the heart beats unusually slowly because of the increased levels of thyroid-stimulating hormone in the blood.
Over time, the heart weakens and cannot pump as hard as it should. In addition, the heart muscles don't relax enough as the heart beats. As a result, the heart weakens and doesn’t pump properly.
People with Hashimoto’s thyroiditis can experience memory problems and difficulty concentrating.
Research hasn’t pinpointed the exact link between mental fogginess and Hashimoto's disease, but low levels of thyroid hormones affect brain areas that deal with cognitive skills and memories. In short, thyroid hormones are vital for proper brain development and function.
In severe cases, the thyroid gland may enlarge (causing a goiter), which can in rare cases cause difficulty swallowing or neck discomfort.
Though related to hypothyroidism, Hashimoto's thyroiditis is different.
Hashimoto's thyroiditis is a problem with your immune system, while hypothyroidism is where the thyroid gland does not produce enough thyroid hormone. In Hashimoto's thyroiditis, the patient's immune system is confused and attacks the thyroid gland, destroying the thyroid tissue and causing a reduction in thyroid hormone.
It can be easy to confuse Hashimoto's thyroiditis and hypothyroidism because they both require testing for thyroid function. However, the test doesn't tell the whole story.
When your immune system attacks and damages thyroid tissue, it might reduce thyroid hormone production. If this happens, a patient can develop hypothyroidism. However, what makes Hashimoto's thyroiditis different is the presence of antithyroid antibodies in the blood.
When Hashimoto's thyroiditis starts, there are likely not to be any obvious signs. Symptoms start to show when the damage to the gland causes insufficient production of thyroid hormone.
Disease progression is gradual and might take years before developing into true hypothyroidism.
If you have any symptoms of Hashimoto's thyroiditis, you should see a doctor for a diagnosis. Your doctor will take a full medical history, perform a physical examination, and carry out blood tests. They may also carry out imaging tests to view the thyroid gland.
Hashimoto's thyroiditis can lead to hypothyroidism. If left untreated, this can lead to the following issues.
Hypothyroidism forces the brain to stimulate the production of thyroid-stimulating hormone (TSH). However, your thyroid cannot use this hormone because of the damage from Hashimoto's thyroiditis.
The accumulation of TSH creates an environment that can cause the thyroid gland to enlarge, causing swelling in the neck known as a goiter. Removing a goiter might require cosmetic surgery.
In extreme cases of gland enlargement, the trachea and esophagus may be affected, hindering breathing and swallowing.
Prolonged untreated Hashimoto's thyroiditis can increase the risk of heart disease.
Thyroid hormone influences the speed and force of the heartbeat and rhythm.
When the thyroid hormone levels are insufficient, the heart rate slows down, premature heartbeats worsen, and heart beats quiver irregularly. For people with underlying heart problems, hypothyroidism can cause heart failure.
Hypothyroidism causes high levels of bad cholesterol (LDL). Even a slight decrease in thyroid hormone is enough to spike LDL.
Normally, thyroid hormones, especially T3, stimulate the breakdown of cholesterol. If someone has hypothyroidism, they have less thyroid hormone to keep levels of bad cholesterol down.
Hypothyroidism weakens the heart muscles, making pumping less efficient. This can lead to high blood pressure.
The thyroid hormone is important for the maturation and function of the central nervous system. When the production of the thyroid hormones is lower, a patient is likely to develop poor memory and an inability to concentrate.
Studies⁶ suggest that many men and women with hypothyroidism experience sexual dysfunction. The effect of low thyroid hormones on libido include:
Depression: As mentioned above, hypothyroidism can lead to depression, which in turn can affect libido.
Lower testosterone levels: People with hypothyroidism may experience reduced levels of testosterone. This hormone is produced by both men and women and is responsible for varying levels of sex drive.
Orgasm disorders: Premature or delayed orgasm for men and women can be caused by thyroid issues.
Painful sex: For women, hypothyroidism can lead to vaginal dryness, which can make intercourse painful.
Erectile dysfunction: This is fairly common, especially for men with hypothyroidism.
Fatigue and weight gain: These symptoms of hypothyroidism can also play a part in reduced libido
Hashimoto's thyroiditis can cause complications during pregnancy. Studies⁷ show that the condition can have many effects on the fetus, including:
Impaired brain development
Low birth weight
Neonatal respiratory distress
Kidney, heart, and brain problems
The effects of hypothyroidism can be reduced on a baby in the womb by assessing women with the condition throughout their pregnancy. Their doctor will carry out regular blood tests and physical examinations to check on thyroid function, and the patient can also watch out for increased symptoms.
Myxedema is a rare complication of severe, untreated Hashimoto’s disease, usually with concurrent infection. Symptoms include drowsiness and lethargy, then ultimately unconsciousness.
At its core, the disease is an autoimmune disease — a condition where the body fights its own tissues and organs. The reason why the body attacks itself has not been established. However, many people with Hashimoto’s thyroiditis have a family history of thyroid problems.
Researchers speculate that Hashimoto’s thyroiditis stems from a combination of genetic and environmental factors.
The possible genetic risk factor for Hashimoto's thyroiditis is variations in several genes belonging to the human leukocyte antigen (HLA) complex family. The gene in the HLA complex helps the immune system differentiate between the body's proteins and invaders like bacteria and viruses.
When a person develops Hashimoto's thyroiditis, the body produces white blood cells to fight the thyroid gland. The white blood cells make proteins called thyroperoxidase (TPO) antibodies which attack and damage the thyroid gland cells.
When most thyroid cells get damaged or die, the thyroid gland fails to make enough hormones to regulate the body's energy. Insufficient levels of thyroid hormone are the primary sign of Hashimoto’s thyroiditis.
Sometimes, however, people have thyroid antibodies but never develop hypothyroidism or show any signs or symptoms.
Other non-genetic risk factors of Hashimoto’s thyroiditis include:
Viral infections such as hepatitis C infection
Some medicines that treat mental health problems like bipolar disorder
Medicines containing iodine, e.g., those used to treat abnormal heart rhythm
Exposure to ionizing radiation
Vitamin D deficiency
A doctor will diagnose Hashimoto's thyroiditis by taking a full medical history, performing a physical examination, requesting certain blood tests, and possibly carrying out an ultrasound examination.
Doctors will be able to diagnose Hashimoto's thyroiditis early if you have a family history of thyroid disease and get regular thyroid function checks.
Doctors first take a full medical history and conduct a physical examination. Since some people with Hashimoto's thyroiditis have a goiter, the doctor will examine your neck for signs of thyroid gland abnormalities.
Your doctor will likely order blood tests to check your thyroid function and rule out other possible diagnoses.
There are three types of blood tests that can lead to a diagnosis of Hashimoto's thyroiditis:
This test checks the thyroid gland's levels of TSH. This hormone tells the thyroid gland to produce more thyroid hormones.
A high level of TSH is a sign of hypothyroidism because the brain is trying to stimulate the thyroid gland to make more hormones.
However, because a person can have normal levels of TSH but still have Hashimoto's thyroiditis, a doctor might order an antithyroid antibodies test.
This test looks for the presence and levels of antibodies that the body mistakenly produces to attack your thyroid gland. The antibodies your doctor will test for include:
Thyroid peroxidase (TPO)
Doctors order antithyroid antibody tests to rule out or confirm Hashimoto's thyroiditis as the cause of hypothyroidism.
This test assesses the amount of thyroid hormone thyroxine (T4) available to body tissue. Low levels of thyroxine hormones show low production of the thyroid hormone.
If your doctor still suspects you have Hashimoto's thyroiditis, they may order an ultrasound of your thyroid gland. An ultrasound will reveal the size of your thyroid gland and whether there are other features of Hashimoto's thyroiditis. Ultrasound eliminates other causes of an enlarged thyroid, such as thyroid nodules.
How your doctor treats you for Hashimoto's disease will depend on the extent of thyroid damage and its effect on hypothyroidism.
If your test shows normal thyroid functions, but TPO antibodies are present, your doctor will not administer any treatment. Instead, you may have regular blood tests to look out for hypothyroidism.
When your blood tests reveal Hashimoto’s thyroiditis, your doctor will suggest thyroid hormone replacement treatment, often in the form of synthetic levothyroxine.
Levothyroxine is a drug identical to natural thyroid hormone. Doctors prescribe levothyroxine orally as a pill, liquid, or gel capsule. The liquid and the gel capsules are helpful for patients with digestive issues that can affect the absorption of the pill.
The treatment is effective at restoring normal hormone levels and alleviating the symptoms of hypothyroidism, and is inexpensive. Many patients with Hashimoto's thyroiditis need to take levothyroxine for the rest of their life.
Establishing the correct dose requires testing. After the first dose, your doctor will repeat your blood tests every four to eight weeks to assess the need for dosage adjustment.
After your doctor establishes the correct dose, you’ll need to have your thyroid-stimulating hormone levels monitored once a year.
If you don’t take enough medication, you could have lower levels of thyroid hormones which will not help you with the symptoms of hypothyroidism. On the other hand, taking too much medication can cause too much thyroid hormone and might lead to other severe effects.
Some supplements, food, and medications can affect how your body absorbs the treatment. Talk to your doctor about other medications or supplements you're taking.
Products that can cause problems with Hashimoto's thyroiditis treatment include:
Treatment for acid reflux — proton pump inhibitors (PPIs)
You're safe taking thyroid medicine on an empty stomach to prevent absorption problems. When taking other medications, you might want to adjust the time of the day you take your thyroid medication.
Hashimoto's thyroiditis is a condition where your body's immune system mistakenly attacks the thyroid gland and damages its cells. The damage makes the thyroid gland produce insufficient hormones, causing hypothyroidism.
Your body doesn’t show signs of hypothyroidism until after the thyroid has been damaged. When you start to notice symptoms, the condition has already infiltrated the thyroid enough to affect its function.
While Hashimoto's thyroiditis has similar symptoms to hypothyroidism, they aren't the same condition. Your doctor will order an antithyroid antibody test to differentiate Hashimoto's thyroiditis from common hypothyroidism.
When your doctor diagnoses you with Hashimoto's thyroiditis, they will provide you with medications and gradually adjust the dose depending on the results of blood tests. It’s important to follow your doctor’s dosage directions to avoid further complications.
The thyroid gland in postmenopausal women: Physiology and diseases (2017)
Hypothyroidism | StatPearl
Chapter 30 thyroid disease and autoimmune diseases | Bench to Bedside
Thyroid hormones and menstrual cycle function in a longitudinal cohort of premenopausal women (2018)
The impact of thyroid disease on sexual dysfunction in men and women (2019)
Thyroid hormone dysfunction during pregnancy: A review (2016)
Hashimoto's disease | National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Hashimoto’s thyroiditis (Lymphocytic Thyroiditis) | American Thyroid Association
Hypothyroidism and memory | Thyroid Advisor
Hashimoto's syndrome | NIH
We make it easy for you to participate in a clinical trial for Hashimoto's disease, and get access to the latest treatments not yet widely available - and be a part of finding a cure.