Undiagnosed Hashimoto’s left woman with lifelong cold hands; experts say a simple blood test can catch it

Emily Measures could not remember a time when her hands and feet were warm. For years the Bristol-based civil servant assumed chronic coldness, brittle nails and sparse eyebrows were quirks of her body or the weather. It was only when her monthly period stopped for five months, and she developed extreme fatigue and “brain fog,” that she went to her GP and was sent for blood tests that led to a diagnosis: Hashimoto’s disease, an autoimmune form of hypothyroidism.

“I was also having really extreme fatigue and brain fog – I felt like my head was full of cotton wool,” Emily said. She received the diagnosis in a letter at a pharmacy and learned she would need lifelong medication. Since starting treatment she said her hair loss, brittle nails and tendency to feel cold have improved, and she became pregnant less than two years later.

Hashimoto’s disease occurs when immune cells mistakenly attack the thyroid gland, reducing its ability to produce hormones that regulate metabolism. Common symptoms include fatigue, weight gain, dry skin, hair loss, muscle weakness and an intolerance to cold. Less common signs can include brittle nails, constipation, a slow heartbeat, a hoarse voice and, in rare cases, inappropriate milk production.

Experts said the disorder is common and often overlooked because its symptoms develop slowly and are non-specific. “Once you or your doctor consider hypothyroidism, then a simple blood test to measure thyroid stimulating hormone (TSH) is enough to make the diagnosis in most cases,” said Dr. Simon Pearce, professor of endocrinology at Newcastle University. “The problem is that the symptoms are very non-specific and they creep up on you gradually over many months or years.”

Estimates of prevalence vary. Hypothyroidism affects roughly two in every 100 adults in the United Kingdom, according to clinicians familiar with the condition, while broader measures of thyroid disorders suggest up to one in 20 people may be affected. Charities and researchers warn that a substantial share of cases remain undetected: a 2019 study of European populations estimated as much as 4.7 percent of people could be living with undiagnosed hypothyroidism, and the American Thyroid Association has estimated that as many as 60 percent of people with thyroid disease may not have been diagnosed.

The exact cause of Hashimoto’s is unknown, but physicians say it frequently runs in families and may be triggered by environmental factors such as infections, certain medications or hormonal changes. If left untreated, hypothyroidism can increase the risk of high cholesterol and heart disease and, in severe cases, may become life-threatening.

Treatment is straightforward in most cases: a daily synthetic thyroxine tablet, or T4, taken in the morning on an empty stomach. “The standard treatment [is] a daily tablet of thyroxine – also known as T4, the main hormone produced by the thyroid gland in the neck – taken in the morning on an empty stomach,” said Professor Ashley Grossman, a consultant endocrinologist. He said most patients feel well once hormone levels are corrected, but a small percentage continue to experience symptoms and may benefit from additional T3 therapy. Those preparations are more expensive, and many GPs are reluctant to prescribe them on the National Health Service, Grossman said.

The slow onset and vagueness of symptoms can delay diagnosis, clinicians said. Patients and doctors may attribute tiredness, constipation or weight gain to lifestyle factors such as stress, parenting demands, poor sleep or diet. That delay can be particularly consequential for women considering pregnancy: thyroid dysfunction can disrupt ovulation and other reproductive hormones and has been linked to higher miscarriage rates. Research from the University of Birmingham cited by clinicians found that thyroid antibodies, as seen in Hashimoto’s, can as much as triple the risk of miscarriage.

Emily said adjusting to a thyroid diagnosis required “a lot of exploration and research,” and that dosages can change depending on life events. “It can change depending on what’s happening in your life, and my last dose was specified down to a half milligram,” she said. After giving birth, she said she and her clinicians had not yet settled on the exact replacement dose.

Clinicians advise that when hypothyroidism is suspected, a TSH blood test is an accessible first step. “Once you or your doctor consider hypothyroidism, then a simple blood test to measure TSH is enough to make the diagnosis in most cases,” Dr. Pearce said. Endocrinologists and patient groups urge awareness of the condition’s varied signs, particularly in women, for whom it is up to 10 times more common.

While most cases respond well to hormone replacement, physicians emphasize the importance of testing and follow-up to avoid complications related to untreated disease and to ensure appropriate dosing during life changes such as pregnancy. Emily Measures’ experience illustrates both the subtlety of early symptoms and the potential for effectively managed treatment to resolve years of unexplained ill health.