Hypothyroidism - Symptoms

Hypothyroidism is a metabolic disorder caused by insufficient secretion of hormones from the thyroid gland. Its symptoms typically develop gradually, initially presenting as mild discomfort, but if left untreated, it can cause serious effects on the entire body system. Understanding the characteristic symptoms is crucial for early diagnosis, as many symptoms can be confused with other chronic diseases.

The symptoms of this disease are mostly related to a decreased metabolic rate, commonly including fatigue, weight gain, and dry skin. Notably, the severity of symptoms is directly related to the duration of the disease; long-term untreated cases may develop complications such as cardiac dysfunction or neurological damage. This article will detail the symptoms at different stages and how patients can determine whether they need medical attention.

 

Early Symptoms and Signs

 

The early symptoms of hypothyroidism usually develop slowly and may be mistaken for general fatigue or stress responses. Patients often exhibit the following mild signs in the initial stages:

 

 
• Persistent fatigue: feeling weak even after adequate sleep, and experiencing weakness after activity
 
• Abnormal temperature regulation: decreased tolerance to cold, often feeling cold in extremities
 
• Weight changes: unexplained weight gain without changes in diet
 

 

These signs may persist for weeks to months, with early symptoms varying among individuals. Some patients may primarily experience gastrointestinal symptoms, such as frequent constipation or bloating. It is also noteworthy that female patients often experience prolonged menstrual cycles or increased menstrual bleeding in the early stages.

 

Potential Physiological Signals

 

Insufficient thyroid hormones can affect multiple physiological functions, with early signs including:

 

 
• Skin and hair changes: skin gradually loses elasticity, becoming dry and flaky; hair may become brittle and break easily
 
• Muscle and joint issues: unexplained stiffness in shoulder or pelvic muscles
 
• Cognitive changes: gradual decline in short-term memory and decreased concentration
 

 

Common Symptoms

 

As the disease progresses to a moderate stage, symptoms become more apparent and affect multiple systems. Common symptoms can be divided into core and secondary categories, with specific manifestations as follows:

 

Core Metabolic Symptoms

 

Thyroid hormones directly regulate basal metabolic rate; therefore, core symptoms include:

 

 
• Decreased metabolic rate: basal body temperature may drop by 0.5-1°C, with a 30-40% reduction in basal metabolic rate
 
• Weight gain pattern: most patients may gain 5-10 kg within 6-12 months without increased food intake
 
• Accumulation of metabolic waste: interstitial fluid retention leading to non-pitting edema, most prominent around the eyes and face
 

 

Systemic Effects

 

Thyroid hormone deficiency affects multiple organ systems, with common manifestations including:

 

 
• Cardiovascular system: reduced cardiac output, heart rate may fall below 50 beats per minute
 
• Gastrointestinal system: slowed intestinal motility causing chronic constipation, with some patients experiencing a 50% or greater decrease in daily bowel movements
 
• Nervous system: gradual impairment of executive functions, with possible decline in spatial orientation and problem-solving abilities
 

 

Disease Progression and Symptom Changes

 

Untreated hypothyroidism gradually worsens over time, affecting more systems. The progression can be divided into three stages:

 

Subclinical Stage Symptoms

 

In the early stage, blood tests show elevated TSH with normal T4 levels, and patients may experience:

 

 
• Mild cognitive impairment: significant decline in efficiency when performing complex tasks
 
• Physical decline: higher rate of shortness of breath when climbing stairs, about 40% higher than healthy controls
 
• Mood fluctuations: 50% of patients report mild depressive tendencies
 

 

Typical Symptom Stage

 

When T4 levels significantly decrease, symptoms show multi-system involvement:

 

The cardiovascular system may show lowered systolic blood pressure and reduced pulse pressure, with some developing pericardial effusion. Blood tests often reveal elevated total cholesterol and LDL cholesterol levels, related to decreased metabolic rate and abnormal lipid metabolism.

 

Advanced Stage Symptoms

 

If untreated, symptoms may reach life-threatening levels, including:

 

 
• Mucopolysaccharide edema syndrome: accumulation of mucopolysaccharides under the skin causing tissue hardening
 
• Cardiac failure: decreased cardiac contractility potentially leading to heart failure
 
• Altered mental state: may develop into stupor or consciousness confusion
 

 

When to Seek Medical Attention

 

If any of the following symptoms occur, immediate medical consultation is advised:

 

 
• Sudden worsening of shortness of breath accompanied by ankle swelling
 
• Slurred speech with difficulty swallowing
 
• Persistent body temperature below 36°C with a heart rate below 50 beats per minute
 

 

It is recommended to schedule a professional examination within two weeks if experiencing:

 

 
• Unexplained weight gain lasting more than two weeks
 
• Abnormal menstrual cycles with non-lactational breast discharge
 
• Recurrent muscle cramps or joint pain without obvious cause
 

 

Special populations should be particularly vigilant, including pregnant women, elderly over 60, and those with autoimmune disease history. Symptoms in these groups may present atypically, such as postpartum women experiencing severe mood swings or abnormal milk secretion.

 

 

 

Frequently Asked Questions

 Why do symptoms of hypothyroidism vary so much among different patients? 

The severity of hypothyroidism symptoms is closely related to the extent of hormone deficiency, disease progression speed, and the patient's metabolic condition. Factors such as age, coexisting illnesses (like cardiovascular issues), or long-term untreated status can make symptoms like fatigue and weight gain more prominent. Individualized treatment plans should be confirmed through blood tests.

  Can dietary adjustments help alleviate hypothyroidism symptoms? 

A balanced diet can assist in treatment, with recommended intake of sufficient iodine (such as seaweed) and B vitamins. However, excessive iodine supplementation may affect medication efficacy and should be done under medical advice. Additionally, raw cruciferous vegetables (like Brussels sprouts) may interfere with thyroid function; it is advisable to thoroughly cook them during treatment.

  Is lifelong medication necessary after taking thyroid hormone replacement therapy? 

The vast majority of primary hypothyroidism cases (such as autoimmune thyroiditis) require lifelong use of synthetic thyroid hormones (e.g., levothyroxine). The medication replaces hormones the body cannot produce on its own and does not repair thyroid damage. Therefore, ongoing treatment with regular blood tests to adjust dosage is usually necessary.

  Is hair loss a symptom of hypothyroidism? How can it be improved? 

Severe hypothyroidism can lead to dry, sparse, or falling hair. Timely treatment usually promotes hair regrowth, but it may take several months. Daily intake of protein and iron-rich foods, avoiding chemical hair treatments, and following medical instructions for medication can help alleviate symptoms.

  Can stress worsen hypothyroidism symptoms? 

Stress affects metabolism and hormone regulation; long-term stress may exacerbate fatigue and low mood. It is recommended to relieve stress through regular exercise, mindfulness practices, and ensuring regular thyroid function monitoring. Adjustments in medication dosage may be necessary to cope with stress-induced metabolic changes.