61 Tumour-induced hypoglycaemia, a rare and often overlooked condition, is emerging as a silent precursor to some cancers, with symptoms sometimes surfacing years before a formal cancer diagnosis. Despite its severity, this unusual cause of low blood sugar remains largely unknown to the public and under-recognised by clinicians. The findings were published in the journal Bratislava Medical Journal. The condition stems from tumours that interfere with normal glucose regulation. In some cases, this is due to excessive insulin production by pancreatic tumours, such as insulinomas, which are rare neuroendocrine growths. In other cases, non-pancreatic tumours produce insulin-like substances or damage organs critical for blood sugar balance. Both forms fall under the broad classification of tumour-induced hypoglycaemia but differ in origin and mechanism. Insulinomas, although generally benign, can cause unpredictable and sometimes severe drops in blood sugar, especially during fasting or physical exertion. Their small size and scattered placement within the pancreas often delay diagnosis, with patients frequently misdiagnosed with neurological or psychiatric conditions before proper testing confirms the underlying issue. Non-islet cell tumour hypoglycaemia presents a different challenge. These tumours, which can originate in the lungs, liver, or uterus, secrete a large, partially processed version of insulin-like growth factor 2. This mimics the action of insulin and suppresses the body’s own hormone responses, leading to prolonged and dangerous episodes of low blood sugar. Such hypoglycaemic events can result in confusion, seizures, or coma and are often mistaken for unrelated medical problems. Doctors typically diagnose tumour-induced hypoglycaemia using prolonged fasting tests or by measuring levels of insulin and its related proteins. Imaging techniques like MRI, CT scans, and more specialised methods are used to locate the offending tumour. In the case of insulinomas, the tumours are frequently found within the pancreas and can be treated with minimally invasive surgery or thermal ablation. The prognosis is generally good when the tumour is localised and operable. For non-islet tumours, treatment is more complex. Because these tumours often grow large before being discovered, surgical removal may not always be possible. When surgery is not feasible, managing the hypoglycaemia becomes the priority. Corticosteroids are often used to counteract the effects of tumour-secreted substances, and growth hormone may also be employed in resistant cases. Some patients may require long-term medical therapy or palliative tumour reduction to maintain glucose stability. The delayed diagnosis common to both forms of this condition presents a significant risk to patients. Often, the first indication is a serious hypoglycaemic event, leading to emergency care and retrospective identification of an underlying tumour. In up to half of all cases, hypoglycaemia occurs before cancer is detected, making it a potentially vital clue in early cancer diagnosis. Awareness of tumour-induced hypoglycaemia remains low, both among patients and many healthcare providers. As understanding of the condition improves, researchers stress the importance of considering unexplained low blood sugar as a red flag for hidden malignancy. With prompt diagnosis and targeted treatment, many patients can achieve lasting relief from symptoms and, in some cases, complete tumour resolution.