These common symptoms include fatigue, sensitivity to cold, hair loss, and constipation. The symptoms are consistent with hypothyroidism, or low thyroid function. But even when Hashimoto’s is already at work, symptoms go unnoticed until inflammation of the thyroid gland—known as chronic lymphocytic thyroiditis—advances.

This article explains what Hashimoto’s feels like and its common symptoms and complications. It also discusses when the symptoms mean you should see a healthcare provider.

Hashimoto’s Symptoms

Hashimoto’s symptoms in the the early stages may include fatigue and weight gain. This is because Hashimoto’s disease affects the thyroid gland’s ability to produce hormones that the body needs to maintain normal metabolism. It limits the ability to convert oxygen and calories into energy.

Though many people with Hashimoto’s have no obvious symptoms in the early stages, some may experience mild swelling at the front of the throat (goiter) caused by the direct inflammation of the gland.

Hashimoto’s disease typically worsens slowly over many years and causes progressive damage to the thyroid gland, leading to a decline in the production of key thyroid hormones.

Hashimoto’s and hypothyroidism don’t exactly mean the same thing, because there are other kinds of low thyroid-function conditions. The symptoms, however, are the same.

The most common include:

FatigueIncreased sensitivity to coldConstipationPale and dry skinA puffy faceBrittle nailsHair loss (alopecia)Enlargement of the tongueUnexplained weight gain despite no change in your dietMuscle aches (myalgia)Joint pain (arthralgia)Muscle weaknessHeavy menstrual bleeding (menorrhagia)Irregular menstruation (oligomenorrhea)DepressionLapses in memory (“brain fog”)Low sex driveGrowth delay in children

Hashimoto’s Complications

Hashimoto’s symptoms don’t always appear immediately but as the disease progresses, it can cause permanent damage to the thyroid gland. In an effort to produce more thyroid hormone, the gland itself will start to enlarge, leading to the development of a goiter.

There are different types of goiter:

Diffuse, characterized by smooth and generalized swellingNodular, characterized by a lumpMultinodular (multiple lumps)Retrosternal (extending backward toward the windpipe)

The progressive metabolic disruptions and hormonal imbalances can begin to affect multiple organ systems, leading to a cascade of complications that extend well beyond the thyroid gland itself.

Infertility

If thyroid hormone levels are too low, they can affect the hormonal mechanisms that regulate the menstrual cycle and trigger ovulation. This can lead to infertility in some cases.

Even with the proper treatment of hypothyroidism, there is no guarantee that fertility can be fully restored in females severely affected by Hashimoto’s.

Heart Disorders

Even mild hypothyroidism can have a profound effect on heart health. The dysregulation of thyroid hormones can instigate increases in “bad” LDL (low-density lipoprotein) cholesterol, leading to the hardening of arteries (atherosclerosis) and increasing the risk of heart attacks and stroke.

While most cases are mild, severe hypothyroidism can lead to a pericardial tamponade, a condition in which the heart is less able to pump blood. In some cases, it can lead to a potentially fatal drop in blood pressure.

Pregnancy Complications

Because a pregnant person’s thyroid hormones are vital to fetal development, untreated hypothyroidism during pregnancy can lead to potentially serious complications for both the parent and child.

According to research, untreated hypothyroidism significantly increases the risk of:

Low birth weightPremature rupture of membranesFetal heartbeat irregularitiesFetal respiratory distress

With these complications is a greatly increased risk of premature birth, between two and four times that of typical pregnancies.

Hashimoto’s Encephalopathy

Hashimoto’s encephalopathy is a rare complication in which the swelling of the brain can cause profound and debilitating neurological symptoms. The condition only affects around two of every 100,000 people each year and usually between the ages of 41 and 44. Females are affected four times more often than males.

Hashimoto’s encephalopathy typically manifests in one of two ways:

A steady decline in cognitive function leading to tremors, sleepiness, confusion, hallucinations, dementia, and, in rare cases, comaSeizures or sudden stroke-like attacks

Myxedema

Myxedema is a severe form of hypothyroidism in which metabolism slows to a point where you can fall into a coma and potentially die. It is associated with untreated disease and can be recognized by characteristic changes in the skin and other organs, including swollen and puffy skin or dropping lids.

Other symptoms of myxedema include:

Severe intolerance to cold A drop in body temperature leading to hypothermia Slowed breathing Hypotension (low blood pressure) Bradycardia (slow heart rate) Slowed movement and delayed reflexes Mental confusion Shock

Myxedema is considered a medical emergency requiring immediate medical assistance.

When to See a Healthcare Provider

As a largely “invisible” disease in the early stages, Hashimoto’s is often first discovered during a routine exam when thyroid hormone levels are found to be abnormally low.

As Hashimoto’s disease tends to run in families, it’s a good idea to get tested if someone in your family has the disease.

Talk to your healthcare provider if you begin to experience the classic signs of hypothyroidism, including persistent tiredness, facial puffiness, dry skin, hair loss, abnormal periods, and unexplained weight gain. Early diagnosis and treatment will improve your outcome.