Health guides

The thyroid is a small gland in the neck that regulates how fast the body works. Its hormones affect metabolism, heart rate, digestion, mood and energy, so an over- or under-active thyroid can cause symptoms in many parts of the body at once.

An underactive thyroid (hypothyroidism) tends to slow things down, causing tiredness, weight gain, sensitivity to cold and low mood, and is usually treated with a daily dose of levothyroxine, adjusted using blood tests. An overactive thyroid (hyperthyroidism), most often caused by Graves' disease, can cause palpitations, weight loss, heat intolerance and anxiety, and may affect the eyes; it is treated with anti-thyroid medication, radioactive iodine or surgery. Thyroid nodules are common and usually benign, assessed with an ultrasound and, if needed, a fine-needle sample.

In type 1 diabetes the body makes little or no insulin and relies on insulin from injections or a pump; type 2 diabetes involves a mix of insulin resistance and reduced insulin production, and is managed with lifestyle, medication and sometimes insulin.

Not everyone fits one of those two. Monogenic diabetes (MODY) is inherited and can need quite different treatment. Latent autoimmune diabetes in adults (LADA) develops slowly in adult life and is often mistaken for type 2. Diabetes can also follow pancreatic disease or surgery, or be caused by steroid treatment. If a diagnosis has never quite seemed to fit, it is worth checking. Some forms of MODY, for instance, respond better to tablets than to insulin.

Technology has changed day-to-day life with diabetes for many people. A continuous glucose monitor (CGM) is a small wearable sensor that reads glucose levels continuously, reducing the need for finger-prick tests and showing trends in real time. A hybrid closed-loop system, sometimes called an “artificial pancreas”, links a CGM to an insulin pump through an algorithm that adjusts insulin automatically around the clock. It does not remove all input: you still tell it about meals and activity, but it can reduce the day-to-day decision-making and help keep glucose in range, with fewer hypos.

Weight is shaped by a mix of hormones, metabolism, sleep, medication, mental health and genetics, and excess weight is now recognised as a medical condition in its own right. A specialist assessment can look for the factors driving it, and for the related conditions that often occur alongside.

A specialist assessment may review thyroid function, insulin resistance and blood glucose, conditions such as PCOS / PMOS, blood pressure, cholesterol and, where relevant, cortisol, alongside a history of eating patterns and previous attempts. Any plan is individual and agreed with you. For people with type 1 diabetes, weight, insulin doses and the risk of hypoglycaemia need to be considered together. Treatment options are discussed at consultation.

A new name. In May 2026, following a global consensus published in The Lancet and led by Professor Helena Teede, the condition long known as polycystic ovary syndrome (PCOS) was formally renamed polyendocrine metabolic ovarian syndrome (PMOS). The old name was misleading: it implied diseased ovarian “cysts” (in fact these are normal, arrested egg follicles) and drew attention away from what the condition really is. That misunderstanding helped delay diagnoses, split care across specialties and add to stigma. The new name reflects the science: polyendocrine (several hormones interact, including insulin and androgens), metabolic (insulin resistance and raised risk of type 2 diabetes and heart disease), and ovarian. Both terms, PCOS and PMOS, will be used side by side during a transition period, so you will see each for some time yet.

What it is. PCOS / PMOS is one of the most common hormone conditions in women of reproductive age, affecting around one in eight. It can cause irregular or absent periods, signs of higher male-hormone levels such as acne or unwanted hair, and is frequently linked with insulin resistance. Diagnosis follows the internationally used Rotterdam approach: two of three features (irregular ovulation, signs or blood markers of androgen excess, and the typical ovarian appearance on ultrasound), together with excluding conditions that can mimic it, such as thyroid disease or a raised prolactin.

The pituitary is a pea-sized gland at the base of the brain that acts as the body's hormonal control centre, directing the thyroid, adrenal glands, growth and reproduction. The adrenal glands, which sit above the kidneys, produce cortisol (the stress hormone), aldosterone (which helps control blood pressure and salt) and adrenaline.

Problems can involve too much or too little of a hormone. Pituitary growths are common and usually benign: some overproduce a hormone (for example, a prolactinoma raising prolactin), while others produce nothing and are picked up incidentally on a scan. Adrenal conditions range from underactivity (too little cortisol) to overactivity, and many are first suspected from abnormal blood tests or an unexpected finding on a scan. Working out the cause relies on careful, step-by-step testing.

The four tiny parathyroid glands behind the thyroid control the level of calcium in the blood through parathyroid hormone (PTH). When one becomes overactive, usually because of a single benign growth, it releases too much PTH and the calcium level rises, a condition called primary hyperparathyroidism.

This is the most common reason for a raised calcium found on routine blood tests, and it becomes more common with age. It is often mild and symptomless, but can cause tiredness, low mood, kidney stones, or, over time, thinning of the bones. Diagnosis is straightforward in principle: measuring calcium and PTH together (with a urine calcium) usually tells the story, and the decision then is whether monitoring or referral for surgery is the better path.

Hypogonadism means the body is not producing enough testosterone, together with symptoms such as low libido, fatigue, low mood or reduced morning erections. It is worth taking seriously and investigating properly, but it is also frequently over-diagnosed, and testosterone levels in the borderline range are common and easily misread.

Assessment aims to establish whether there is a genuine, confirmed deficiency, and to look for the cause. That means a morning blood test (repeated to confirm), measuring LH and FSH to distinguish a problem in the testes (primary) from one in the pituitary or hypothalamus (secondary), checking prolactin, and looking for common contributors such as excess weight, type 2 diabetes or sleep problems, which, when addressed, often improve testosterone on their own.

Assessment comes first. The aim is to reach the right diagnosis and identify any underlying cause, and treatment is considered only where it is clinically appropriate. Testosterone is not prescribed on request or for performance enhancement.