Thyroid vs. Thymus Problems Differences and Similarities

Picture of the thyroid gland and thymus organ.

• Other than having similar-sounding names, there is absolutely no connection or similarity between the function of the thyroid and the thymus glands. 
• The thyroid is an endocrine gland that makes thyroid hormone.
• The thyroid is a butterfly-shaped gland located in the lower front of the neck. 
• A normal, healthy thyroid gland may not be palpable, but an enlarged thyroid can be felt in the neck.
• Thyroid hormone helps control the body’s metabolism, which are the chemical processes in the  body that 
  • help the body,
  • use energy, 
  • regulate body temperature, 
  • maintain body weight, and 
  • keep the brain, heart, lungs, muscles, and other organs working properly. 

It is possible to live without a thyroid gland, but it is necessary to take thyroid hormone replacement medications. You cannot live without thyroid hormones. 

• The thymus is a small organ located just behind the breastbone, in the space in the chest between the lungs, in front of and above the heart. 
• The thymus is part of the body’s immune system, but it is only active until puberty.
• After puberty the thymus decreases in size and is replaced by body fat. 
• The thymus organ is critical for immune function until puberty, after which it decreases in size and is replaced by fat.
• Adults essentially live without a functioning thymus organ. 
• Problems with the thymus gland can lead to cancer.

Symptoms and Signs of Hyperthyroidism

Symptoms of overactive thyroid (hyperthyroidism) include:

1. Weight loss without trying
2. Increased heart rate or palpitations
3. Increased blood pressure
4. Nervousness
5. Increased sweating
6. More frequent bowel movements (sometimes diarrhea)
7. Muscle weakness
8. Tremor
9. Swollen thyroid (goiter)
10. Lighter or shorter menstrual periods

Symptoms and Signs of Hypothyroidism

Symptoms of underactive thyroid (hypothyroidism) include:

1. Lethargy/fatigue
2. Depression
3. Slow heart rate
4. Increased sensitivity to cold
5. Numbness or tingling in the hands
6. Swollen thyroid (goiter)
7. Constipation
8. Changes in menstrual periods
9. Dry skin
10. Hair loss
11. Weight gain

Symptoms and Signs of Thymus Problems

Symptoms of thymus problems depend on the cause and may include: 

1. Reduced resistance to infectious diseases
2. Muscle fatigue
3. Drooping eyelids
4. Difficulty breathing
5. Shortness of breath
6. Cough (with bloody sputum)
7. Chest pain
8. Difficulty swallowing
9. Dizziness
10. Loss of appetite
11. Weight loss
12. Headache
13. Swelling of head face or neck
14. Bluish color to the skin 

Causes of Hyperthyroidism

Causes of hyperthyroidism include:

• Graves' disease, which causes overproduction of thyroid hormone
• Toxic nodular or multinodular goiter characterized by nodules or lumps in the thyroid that grow and cause thyroid hormone output to increase.
• Thyroiditis is caused by a problem with the immune system or a viral infection that causes the gland to leak stored thyroid hormone; and taking too much thyroid hormone in tablet form.

Causes and Risk Factors for Hypothyroidism

Causes and risk factors of hypothyroidism include:

• Autoimmune disease (Hashimoto’s thyroiditis).
• Surgical removal of part or all the thyroid gland, radiation treatment.
• Congenital (from birth) hypothyroidism.
• Thyroiditis.
• Certain medications.
• Too much or too little iodine
• Damage to the pituitary gland. 
• Rare disorders that infiltrate the thyroid

Thyroid Problems and Diseases Risk Factors

Risk factors for thyroid diseases include:

• Past thyroid problems
• Surgery or radiotherapy affecting the thyroid gland
• Goiter. 
• Anemia.
• Type 1 diabetes.

Causes and Risk Factors for Thumus Problems

Causes and risk factors for thymus problems and diseases include:

• Genetic abnormalities. Autoimmune disorders. Cancer.  
• Age (seen more commonly in adults in their 70s) and ethnicity (more common in Asians and Pacific Islanders). 
   

Thyroid Diseases and Problems Diagnosis

Thyroid diseases are diagnosed starting with a health history and physical, which may include checking the neck for thyroid nodules.

A doctor may also order tests such as: 

• Blood tests for thyroid-stimulating hormone (TSH). 
• Radioactive iodine uptake test.
• Thyroid scan.
• Thyroid ultrasound.
• Thyroid fine needle biopsy.

Thymus Cancer Diagnosis

• In many people with thymus cancer, there are no symptoms, and tumors are found by chance on imaging tests such as chest X-rays or CT scans done for other reasons. 
• Other tests that may be performed to diagnose thymus problems include:
  • Magnetic resonance imaging (MRI)
  • Positron emission tomography (PET) scan

Treatment for thyroid conditions depends on the disease. 

Hyperthyroidism Treatment

Hyperthyroidism is treated and managed with:

• Antithyroid medications.
• Beta-blocker drugs.
• Radioiodine treatment.

In severe cases, surgical removal of the thyroid gland (which may result in permanent hypothyroidism).

Hypothyroidism Treatment

• Hypothyroidism is treated with thyroid hormone replacement medication. 
• Goiter is treated with medications. 
• Thyroid Nodules Treatment

Thyroid Nodules Treatment

Thyroid nodules may require no treatment. When treatment is needed, surgery may be used to remove nodules, or radioiodine may be used to shrink nodules. 

Thyroid Cancer Treatment

Thyroid cancer treatment usually involves surgical removal of part or all of the thyroid gland and radioiodine therapy after surgery. 
 

Surgery to treat thymus cancer, and if necessary, removal of the thymus organ.

• It may be necessary to have radiation therapy before thymus cancer surgery. 
• Thymus cancer surgery followed by radiation therapy with or without chemotherapy.
• If thymus cancer cannot be completely removed by surgery treatment options like:
  • Chemotherapy treatment
  • Chemotherapy treatment with radiation therapy.
  • Chemotherapy treatments surgery include:
  • Chemotherapy or no chemotherapy. 
  • Removing the tumor and then radiation therapy. 

Thyroid Cancer Cure and Life Expectancy

• Most types of thyroid cancer have a very high cure rate. 
• Papillary thyroid cancer.
• Follicular thyroid cancer.
• Medullary thyroid cancer has nearly a 100% 5-year survival rate. That means almost all patients will be alive 5 years following diagnosis if the cancer is localized. 
• If the thyroid cancer spreads to nearby areas, the 5-year survival rate for these types of thyroid cancers ranges from 90 to 99%. 
• Anaplastic thyroid cancer is harder to cure. The 5-year survival rate for localized anaplastic thyroid cancer is just 31%.

Thymus Cancer Cure and Life Expectancy

Thymus cancer is treated with:

• Surgery.
• Radiation therapy.
• Chemotherapy.

Thymus cancer that is localized has a 92% 5-year survival rate. If the thymus cancer spreads to nearby areas, the 5-year survival rate is 77%.