Detecting and Treating Subclinical Hyperthyroidism

Table of Contents

Subclinical hyperthyroidism is the term used to describe low or undetectable levels of thyroid stimulating hormone (TSH) with normal triiodothyronine (T3) and thyroxine (T4) levels. While it’s not technically hyperthyroidism, it could develop into it.

TSH is a hormone released by the pituitary gland in the brain and is directly linked to the production of T3 and T4 by the thyroid. In cases where the underlying causes of low TSH levels are not addressed, subclinical hyperthyroidism can develop into overt hyperthyroidism if T3 and T4 levels become too high.

In subclinical hyperthyroidism your T3 and T4 levels are normal. In hyperthyroidism, you have excessive amounts of T3 and T4. If your T3 and T4 levels are normal, you do not have what is known as “overt hyperthyroidism.”

“Subclinical” means the condition is not severe enough yet to be fully defined as a clinical condition. Subclinical hyperthyroidism only becomes hyperthyroidism in some cases. 

Now that you have a better understanding of what is meant by subclinical hyperthyroidism, let’s learn more about symptoms, causes, and what can be done about it.

There are often no symptoms that are super noticeable or obvious. In other words, for many, subclinical hyperthyroidism is asymptomatic. 

Essentially, subclinical hyperthyroidism presents as a mild form of hyperthyroidism. 

You may experience mild signs like:



• Nervousness
• Increased heart rate
• Heat intolerance
• Weight loss
• Increased appetite
• Frequent bowel movements/diarrhea
• Menstrual changes

While there’s no single cause of subclinical hyperthyroidism, the causes are generally the same as hyperthyroidism and include:

• Overtreatment of hypothyroidism with thyroid hormone replacement therapy
• Multinodular toxic goiter
• Graves’ disease
• Inflammation of thyroid
  
  

Fortunately, simple changes in diet and lifestyle can often make a big difference in your thyroid health. A professional nutritionist specializing in thyroid issues can provide guidance to dysregulated thyroid hormone levels. Learn more about natural treatment for hypothyroidism or hyperthyroidism at HealthierU.

Anyone can get subclinical hyperthyroidism, but those most at risk include people receiving thyroid hormone replacement therapy for hypothyroidism and people over the age of 65. 

Individuals over 65 have a higher chance of developing hyperthyroidism because as we age, the thyroid gland undergoes natural changes that can increase the likelihood of producing too much thyroid hormone. 



The development of thyroid nodules is more common in older adults, which can cause the thyroid to become overactive, leading to hyperthyroidism. Older individuals may also experience subtle symptoms that seem a part of the normal aging process, delaying diagnosis.

If something feels off in your body, listen! Consult with a holistic health practitioner like Dr. Donna Sergi at HealthierU to find out what is going on and address problems before they become more severe. 

Diagnosis is made after conducting bloodwork to determine thyroid function. 

Normal TSH range is 0.4-4.5 mIU/L for a non-pregnant adult. If results show TSH is low or undetectable, you will be diagnosed with mild or severe subclinical hyperthyroidism, depending on the level. 

Determining if your case is mild or severe comes down to a specifically defined range of TSH levels:

• Mild: Low but detectable TSH (0.1-0.4 mIU/L), which accounts for about 65-75% of people with subclinical hyperthyroidism
  
  
• Severe: Less than 0.1 mIU/L, which accounts for approximately 25-35% of people with subclinical hyperthyroidism

Not generally, but you can be sure you’re getting enough iodine, without getting too much. This isn’t typically a problem in the US, which is why subclinical hyperthyroidism isn’t as common here as in places with iodine deficiencies. 



If you notice changes in how you feel, see a holistic health practitioner or doctor as soon as possible for testing. With many illnesses and health conditions, waiting too long to look into symptoms can lead to more severe cases and more difficulty in treatment. If you are diagnosed with a thyroid condition, a holistic practitioner like HealthierU can help you improve thyroid function naturally.

There’s disagreement regarding the treatment of subclinical hyperthyroidism due to a lack of research. Many providers offer a “wait and see” approach and if it doesn’t resolve, they intervene. 

If TSH levels are persistently under 0.1 mIU/L, some providers will encourage treatment, especially if the individual being treated is:



• Aged 65 or over
• Postmenopausal, younger than 65, and not taking estrogen or bisphosphonates
• Younger than 65 but has heart disease, osteoporosis, and/or other hyperthyroid symptoms

It’s typically safe to live with subclinical hyperthyroidism unless you fall into one of the categories mentioned above. The chance of the condition progressing into hyperthyroidism is low, but higher in people with very low TSH levels.

You should be aware that subclinical hyperthyroidism can be associated with other conditions, including:

• Atrial fibrillation
• Heart failure
• Coronary heart disease
• Bone loss and fractures



Dementia, especially if you are 65+ with severe subclinical hyperthyroidism.

Many people live with subclinical hyperthyroidism, and it can resolve on its own. However, if you have a toxic goiter or nodule in your thyroid, your providers may want to treat it. This is often done with oral radioactive iodine. The iodine absorbed by the overactive thyroid cells damages them, helping shrink your thyroid and bring your hormone levels down to a normal range.

If you have Graves’ disease, a combination of antithyroid drugs and radioactive iodine is the preferred treatment. The iodine damages the cells, while the antithyroid drugs block your thyroid’s ability to make hormones.

In less severe a consultation with a natural health practitioner like Dr. Sergi at HealthierU is still advisable. They’ll be able to provide valuable insight into diet and lifestyle changes that can improve symptoms and potentially result in TSH levels returning to the normal range. 

Changes to your diet and lifestyle may improve your thyroid levels, especially with healthy supplementation. If you have been diagnosed with mild or severe hyperthyroidism, you are not in it alone. 

At HealthierU, we are here to help get to the cause of your problem naturally, safely, and effectively. 

We start by taking a comprehensive medical history and providing an in-depth nutrition consultation. We’ll then recommend organic, whole-food concentrates that supplement your dietary and lifestyle changes and can help speed recovery. 

Dr. Sergi is a specialist in women's health and wellness with decades of experience as a Nutritionist and a Holistic Chiropractor. She’s committed to helping her patients get well — and stay healthy, with nutrition and lifestyle guidance. 

Schedule your initial appointment today, and together, let’s find a solution for your subclinical hyperthyroidism.