
A routine health check often brings a confusing line: TSH slightly high, T3 and T4 normal. The doctor calls it “borderline.” The patient feels mostly fine. The report is folded away.
But thyroid disorders are not rare in India. A large multi-city study published in the Indian Journal of Endocrinology and Metabolism in 2014 found that nearly 1 in 10 adults in India have hypothyroidism, and around 8-9% have subclinical hypothyroidism. The study covered eight major cities and over 5,000 participants. That is not a small number.

Data from the Indian Council of Medical Research (ICMR) and other national surveys continue to show that thyroid disorders are among the most common endocrine problems in the country, especially in women.
Yet borderline thyroid reports are often ignored. Why?

A borderline or subclinical thyroid report usually means that TSH is mildly elevated or mildly suppressed, but T3 and T4 levels remain within the normal range.
It does not scream disease. It whispers risk.
We spoke to Dr Vandana Boobna, Director, Internal Medicine, Max Super Speciality Hospital, Shalimar Bagh, who explained, “In India, it is very common to have deranged thyroid reports and in spite of having the deranged thyroid reports which is neither in the range of hyper or hypothyroid, it is called subclinical thyroid reports where the thyroid is borderline deranged and it is mostly ignored by the people because it has some value but since it doesn't cause much of the symptom, the patient remains unaware of it and the disease remains unnoticed.”
The danger lies in the trend. A single number may not matter. A pattern over time does.

Several factors make India a high-risk zone for thyroid issues:
Iodine history
India was once known as an iodine-deficient belt. The government introduced universal salt iodisation decades ago, which reduced severe deficiency. According to the Ministry of Health and Family Welfare, iodised salt coverage has improved significantly. But shifts in iodine intake can also influence thyroid patterns, especially autoimmune conditions.
Autoimmune thyroiditis
Autoimmune causes, such as Hashimoto’s thyroiditis, are increasingly common. In this condition, the body attacks its own thyroid gland.
Ageing population
As life expectancy increases, thyroid dysfunction becomes more frequent. Even mild shifts in hormone levels can appear with age.
Environmental and lifestyle stressors
Urban pollution, stress, and metabolic conditions such as obesity may influence thyroid balance.
Dr Boobna adds that autoimmune derangements, ageing, environmental factors, thyroid infections, prior thyroid surgery, and radiation exposure can all push thyroid levels into borderline zones.

Thyroid disease does not affect men and women equally. Women are far more likely to develop it.
Life stages play a role.
Pregnancy planning, pregnancy itself, postpartum changes, and perimenopause all involve hormonal shifts. These shifts increase the body’s demand for thyroid hormone.
Dr Boobna notes, “Since females are having different stages in their life, they are more prone to have thyroid illness in their system because during pregnancy, planning the pregnancy, the hormonal imbalance, they all affect thyroid hormone and during pregnancy or planning the pregnancy, the requirement of thyroid hormone becomes more in the body.”
Untreated thyroid imbalance during pregnancy can affect both mother and baby. This is why many obstetricians now recommend thyroid screening during early pregnancy.

Borderline thyroid often causes subtle or no symptoms.
A little fatigue. Mild weight gain. Hair fall. Slight mood shifts. Many people blame work stress, poor sleep, or ageing.
But here is the question: if there are no symptoms, does it matter?
Yes, it does. Subclinical hypothyroidism can slowly progress to overt hypothyroidism. Research shows that patients with positive thyroid antibodies are at higher risk of progression over time.
Dr Boobna cautions, “So, unless until we follow the trend, we will not able to know. Similarly, when your euthyroid can become subclinical and when subclinical can become overt thyroid, you will never know.”
Thyroid health is not about one report. It is about tracking change.

There are specific situations where thyroid testing is essential, even if there are no symptoms:
Planning pregnancy
Currently pregnant
PCOD or menstrual irregularities
Obesity or unexplained weight gain
History of neck radiation
Thyroid surgery
Recent viral infection
Cardiac surgery near the neck
Dr Boobna stresses that these are not optional checks. They are preventive steps.
In people with autoimmune thyroiditis, there may be a temporary rise in thyroid hormones followed by a drop into hypothyroidism. Without follow-up testing, this shift may go unnoticed.

First, repeat the test after 6-12 weeks if advised. Thyroid values can fluctuate.
Second, ask for thyroid antibody testing if autoimmune disease is suspected. This helps predict future risk.
Third, review lifestyle factors. Iodine intake should neither be too low nor excessive. A balanced diet with iodised salt is usually sufficient in urban India.
Fourth, monitor weight, menstrual cycles, heart rate, and energy levels. These are simple but useful clues.
Not everyone with borderline thyroid needs medication. Treatment depends on TSH levels, age, symptoms, pregnancy status, and antibody results. This decision should always be personalised.

Thyroid disease is not dramatic like a heart attack. It moves quietly. It alters mood, metabolism, fertility, and heart health over time.
The 2014 multi-city Indian study showed that over 42 million Indians may be suffering from thyroid disorders. That number alone calls for awareness.
Borderline reports are not a reason to panic. But they are a reason to pay attention.
A simple follow-up test every few months can prevent years of fatigue, metabolic struggle, and reproductive complications.
The thyroid may be small. Its impact is not.
Medical experts consulted
This article includes expert inputs shared with TOI Health by:
Dr Vandana Boobna, Director, Internal Medicine, Max Super Speciality Hospital, Shalimar Bagh
Inputs were used to explain why borderline thyroid reports are often ignored and why timely testing and regular follow-up are essential to prevent progression.