What are the symptoms and treatment options for hypothyroidism?

Symptoms of Hypothyroidism

The common symptoms of hypothyroidism include fatigue, cold intolerance, weight gain, dry skin, constipation, voice changes, mental impairment, and irregular menstrual cycles, which result from decreased metabolic rate due to insufficient thyroid hormone production. 1, 2

Clinical Presentation

Hypothyroidism presents with a spectrum of symptoms that vary in severity:

Common Physical Symptoms

• Cold intolerance
• Fatigue and lethargy
• Weight gain despite unchanged diet
• Dry skin (xeroderma)
• Constipation
• Voice changes (hoarseness)
• Edema (especially periorbital)
• Bradycardia
• Hair loss or brittle hair
• Muscle aches (myalgias)

Cognitive and Psychological Symptoms

• Mental impairment/poor concentration
• Depression
• Memory problems

Reproductive Symptoms

• Irregular menstrual cycles
• Infertility
• Decreased libido

Laboratory Findings

• Elevated TSH (>4.5 mIU/L)
• Low Free T4
• Possible hyperlipidemia

Severity Classification and Management

Grade 1 (Mild/Subclinical)

• TSH >4.5 and <10 mIU/L with normal Free T4
• Often asymptomatic
• Monitor TSH every 4-6 weeks 3
• Treatment generally not required unless TSH >10 mIU/L or TPO antibodies are elevated 1

Grade 2 (Moderate)

• TSH persistently >10 mIU/L
• Moderate symptoms affecting daily activities
• Requires thyroid hormone supplementation
• Monitor TSH every 6-8 weeks while titrating dose 3

Grade 3-4 (Severe)

• Severe symptoms with significant life impact
• May progress to myxedema coma (life-threatening)
• Requires immediate treatment and possible hospitalization
• Symptoms include bradycardia, hypothermia, and altered mental status 3

Treatment Approach

Levothyroxine replacement is the standard treatment:

• Starting dose: 1.5-1.6 mcg/kg/day for most adults 4, 1
• For elderly (>70 years) or those with cardiac disease: Start lower at 25-50 mcg/day 3, 5
• Take on empty stomach, 30-60 minutes before breakfast 4
• Avoid medications that interfere with absorption (calcium, iron supplements, PPIs) 4, 5
• Monitor TSH every 6-8 weeks while titrating dose, then every 6-12 months once stable 4

Special Considerations

Pregnancy

• Increase levothyroxine dose by approximately 30% when pregnancy is confirmed 4, 1
• Take one extra dose twice weekly (9 doses per week total) 1
• Monitor TSH monthly during pregnancy 4

Elderly Patients

• Start at lower doses (12.5-50 mcg/day)
• Increased risk of cardiac complications with overtreatment 5, 1
• Monitor for atrial arrhythmias, especially atrial fibrillation 5

Common Pitfalls to Avoid

1. Misattribution of symptoms: Many hypothyroidism symptoms are nonspecific and overlap with other conditions 6
2. Inadequate monitoring: Failure to adjust dose based on TSH levels
3. Medication interactions: Several medications affect levothyroxine absorption or metabolism 5
4. Overtreatment: Can lead to iatrogenic hyperthyroidism with cardiac complications
5. Undertreatment: Persistent symptoms and increased cardiovascular risk

When to Consider Specialist Referral

• Unusual clinical presentations
• Concern for central hypothyroidism
• Difficulty titrating hormone therapy
• Persistent symptoms despite normalized TSH
• Myxedema coma (requires immediate hospitalization)

Remember that hypothyroidism is usually a permanent condition requiring lifelong treatment, with the exception of postpartum thyroiditis which may be transient 7.