Typically, the onset of hypothyroidism occurs gradually; in other words, this condition develops slowly over time. This gradual development is why it can take years for any notable signs or symptoms to develop. Nonetheless, there are occasions when it only takes a few months for the signs and symptoms of hypothyroidism to become apparent.


Some of the most common symptoms of underactive thyroid include:

  • Decreased perspiration
  • Intolerance to the cold
  • Decrease in appetite
  • Weight gain, despite a decrease in food consumption
  • Irregular/unpredictable menstrual cycles
  • Increase in menstrual blood flow
  • Puffy-looking eyes
  • Constipation
  • Overly dry hair and skin
  • Voice deepening
  • Fatigue, drowsiness, and/or sleepiness
  • Muscle weakness
  • Slowed speech, thought and/or action
  • Muscle aches
  • Slow reflexes (hyporeflexia)
  • Bloated-looking face
  • Thinning hair
  • Depression
  • Infertility
  • Goiter (enlarged thyroid)
  • Slow heart rate (bradycardia)

Other Signs and Complications

Other signs and complications of hypothyroidism can include the following.

Pericardial Effusion

In the later stages of this disorder, pericardial effusion may develop. This condition is characterized by fluid accumulating around the heart.

Delayed Development or Disability

When a very young child has an underactive thyroid, intellectual disability can result. Unfortunately, delayed growth can occur in children of any age with this condition.

Myxedema Coma

In rare instances, myxedema coma (aka myxedema crisis) can result. This life-threatening complication requires seeking immediate medical attention. 

This complication is characterized by:

  • respiratory depression,
  • a low body temperature (i.e., hypothermia), and
  • the inability to respond.

Myxedema crisis is frequently precipitated (caused) by:

  • an infection,
  • exposure to cold, and/or
  • the intake of drugs used for sedation purposes.

This complication occurs most frequently in seniors, with elderly women especially being prone to this problem.

Symptoms of Certain Types of Underactive Thyroid

Of course, specific forms of hypothyroidism can present distinct symptoms.

Atrophic Thyroiditis

This form of hypothyroidism can remain undiagnosed for years, only becoming evident once abnormalities present on patients’ routine thyroid function tests or after the thyroid gland shrinks in size and hardens.

The symptoms associated with this latter stage of autoimmune thyroiditis include, but are not limited to, the following:

  • Thinning of the skin
  • A decrease in sweating (hypohidrosis)
  • Hyperkeratosis, or thickening of the stratum corneum (outermost layer of the epidermis, which itself is the outermost layer of the skin) due to an abnormal quantity of keratin
  • Entrapment syndromes like carpal tunnel

Atrophic thyroiditis becomes evident in the later stages of hypothyroidism; therefore, the individual’s neurological and cardiac functions are usually already impaired.

Congenital Hypothyroidism

Children who have congenital hypothyroidism may display the typical symptoms associated with hypothyroidism as well as some symptoms that are generally attributed to neonates (newborns).

Typical symptoms associated with congenital hypothyroidism and neonates include:

  • An umbilical hernia
  • Prolonged jaundice
  • Floppy infant syndrome (hypotonia)
  • A hoarse-sounding cry
  • Poor feeding habits
  • A decrease in or the absence of a neonate’s ability to feel thirsty (aka adipsia or hypodipsia)
  • An unusually large tongue (macroglossia)
  • A decrease in the neonate’s activity level
  • Congenital iodine deficiency syndrome

This last symptom—congenital iodine deficiency syndrome—presents its own set of issues. Specifically, this syndrome negatively affects the development of the skeleton and the brain, which can result in:

  • intellectual disabilities,
  • delayed closure of the fontanelle (space between newborns’ bones in the skull), and/or
  • short stature.


What are early warning signs of thyroid problems?

Sometimes, there are no warning signs for several years. However, when signs and symptoms do present, the most common ones include:

  • irregular menstruation,
  • cold intolerance,
  • an increased menstrual flow,
  • a decrease in one’s appetite,
  • weight gain,
  • decreased perspiration,
  • constipation,
  • deepening of the voice,
  • coarse hair,
  • puffy-looking eyes, 
  • and overly dry skin.

How can I check my thyroid at home?

There are at-home tests available that only require a drop of blood for testing. Once ordered, the test arrives through the mail. When it arrives, the individual performs a fingerstick to collect a small amount of blood. After collection, the individual mails this sample to a lab where, in turn, physicians review it. Eventually, the patient will learn their results based on this lab analysis.

These at-home tests aren’t the only way that people check their thyroid function outside the doctor’s office, though.

Some doctors, for example, state that looking at one’s fingernails and/or toenails can help determine if a patient has an underactive thyroid. Signs to look for include:

  • nail splitting,
  • rough, ragged nail edges, and
  • vertical white ridges.

Another way to check the thyroid? Some say to swallow while looking in the mirror. This method involves closely examining the Adam’s apple to see if the thyroid appears inflamed. In addition, while tipping the head backwards, individuals should swallow and look for bulges or lumps in the neck area as well as in the area above the collarbone.

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.

More about Hypothyroidism

Written by

Fact Checked by