A tired woman rests on the floor with a mopAt this point in history, who could say no to an extra few hours of sleep or a nice afternoon nap?

However, if you’ve been feeling run down for months, tired without reason, exhausted on a daily basis or unusually low in energy, you’ve probably considered going to your doctor for a check-up.

Sick and tired of being sick and tired?

By itself, persistent fatigue is a serious matter that can significantly impair your life, relationships, and physical and mental health. If that wasn’t bad enough, it can also be a portentous symptom of a serious underlying problem.

If ongoing fatigue has been affecting you for a while, it’s a good idea to try and figure out what’s going on.

When you start looking into the causes of fatigue, one of the first things that friends, strangers, the internet, and your own GP will advise is to check your thyroid.

The gland of plenty

A man happily adjusts his bow-tie, which sits in the approximate location of his thyroidThe thyroid gland is a small but important organ situated at the lower front of the throat and shaped like a novelty bow-tie. Its job is to produce and secrete hormones – chemical messages that a body uses to communicate with itself and co-ordinate all its different parts.

While these hormones are tiny, they’re also very powerful.

The two main hormones the thyroid makes, T3 and T4, are extremely important in affecting a person’s metabolism, appetite, ability to absorb nutrients and medication, blood flow and body temperature, sexual function, energy, and the growth of children and teenagers, among other things.

This means that if a thyroid doesn’t perform its job perfectly, it can have a wide range of effects across a person’s body.

A balancing act

There are two main ways the thyroid can malfunction.

It can become overactive, secreting too many hormones too quickly, which raises a person’s metabolism. This condition is known as hyperthyroidism, and its symptoms can include weight loss, a racing heartbeat, and feeling shaky, anxious, hungry, and fatigued.

The thyroid can also become underactive, not secreting enough hormones, which lowers a person’s metabolism. This condition is known as hypothyroidism and its symptoms can include brain fog, depression, a slow heart rate, feeling cold all the time, weight gain, dry hair and skin, and feeling fatigued.

A simple blood test is all that’s usually needed to diagnose hyper- or hypo-thyroidism. If your hormone levels are too high, you probably have hyperthyroidism. If your hormone levels are too low, you probably have hypothyroidism. If your hormone levels are normal, your thyroid is probably chugging along fine.

But what if your tests show that something’s slightly off, and so your results can’t be neatly categorised as perfectly normal or clinically abnormal?

Subclinical hypothyroidism

If your thyroid hormones are just a little bit lower than the normal range, your doctor might have mentioned subclinical hypothyroidism. While “Hypothyroidism” refers to a low level of thyroid hormone, “Subclinical” means the level isn’t quite low enough to hit the threshold for diagnosis.

Subclinical hypothyroidism often shows no symptoms and most people with it don’t even know they have it. It’s actually a sign that the body’s usual checks and balances are working, as parts of the endocrine system (the network of glands and organs that control hormones) compensate for other parts. It means the body’s not going about the usual way of doing things, but it’s still getting the job done.

For years the topic of subclinical hypothyroidism and whether it needs to be treated at all has been a topic of discussion in the medical community. Recent studies by Dr Samuels and her research team at the Oregon Health & Science University in Portland have helped to solve this problem by testing a range of hypothyroidism patients with varying levels of medication.

They found that there actually wasn’t a different between patients’ energy expenditure or body composition when their medication was adjusted to bring their hormone levels to almost-normal values compared to normal values. They did find that patients felt better when they thought they were on the highest dose of medication, whether they actually were or not.

In short, most cases of subclinical hypothyroidism don’t show symptoms, don’t usually benefit from medication, and mostly resolve on their own. This means for a person trying to find the solve the case of their fatigue, slightly abnormal thyroid results are usually a red herring.

What’s going on then?

Someone holds a magnifying glass up to the skyUnfortunately, fatigue is an extremely common symptom of many health conditions and so pinning down a cause can often be more of a marathon than a sprint.

Along with your thyroid levels, your doctor might also test you for things like heart disease, kidney and liver function, infection, or depression, anxiety. These, along with many other diseases, also cause fatigue.

Fatigue can also be a result of stress and burnout, or a result of overwhelming life circumstances. It can even be a combination of many things going on at once.

If, for example, if you catch a virus during a time of higher work stress while worrying about affording the month’s rent in the context of a rapidly changing climate, you might feel more fatigue and take longer recovering than if you caught a virus in easier circumstances.

Living with a mysterious health problem is difficult, and it’s easy to fall down rabbit holes looking for resolution. Thyroid disease can seem like an obvious answer as one of its main symptoms is fatigue, and it’s easy to test for and simple to treat.

However, if your thyroid results aren’t clearly clinically abnormal or you’re already receiving treatment for thyroid issues, there might be another cause of your fatigue.

Managing fatigue

A woman has a cosy napDon’t give up looking for answers, but look out for yourself as well.

If your GP isn’t supportive, consider raising your concerns or find a different GP. Prioritise yourself and your energy levels for a while. Avoid stress as much as you can, and do things you enjoy. Take a little exercise and don’t exist entirely on takeaway meals. Make time and space for good sleep, and good relationships. And lastly, realise that fatigue will take time to resolve, so be gentle and kind with yourself while you recover.