Dr Amir Khan, a regular health expert on ITV's Lorraine and Good Morning Britain, has explained the difference between being 'busy tired' and 'medically tired' in a recent TikTok video. He says knowing that difference 'can literally change your life'.
What is 'busy tired'?
Dr Khan described 'busy tired' as the fatigue that follows long days, late nights, stress, kids, or Netflix binges. This kind of tiredness usually improves after a good night's sleep or a weekend of rest, leaving you feeling refreshed.
However, if you are constantly exhausted even after quality sleep, wake up feeling tired or foggy, cannot concentrate, or need caffeine just to get through the day, he suggests it may be worth looking into a medical cause.
Common medical causes of persistent tiredness
The first possible reason Dr Khan outlined is anaemia, which he described as having a low red blood cell count. Low iron is a common type, meaning less oxygen reaches your cells, leaving you feeling weak, dizzy, and short of breath when climbing stairs.
Low Vitamin D levels are another potential cause, particularly in the UK during darker months when sunlight exposure is limited. Dr Khan noted that low Vitamin D can leave you feeling constantly tired, achy, and low in mood, and recommended taking a Vitamin D supplement.
Thyroid problems can also lead to persistent tiredness. An underactive thyroid slows everything down, affecting energy, mood, and even digestion.
Sleep apnoea and mental health
Sleep apnoea, where breathing stops during sleep, is another condition to consider. Dr Khan explained that oxygen levels drop overnight, leaving you unrefreshed in the morning. It is often seen in people who are overweight, snore, or whose partner notices them stopping breathing during the night.
Depression and low mood can also cause what Dr Khan called 'mental health fatigue' – a heavy tiredness that does not shift even when life feels calm.
He added that more serious conditions, such as cancer, could be the cause in rare cases. He urged anyone feeling tired alongside unexplained weight loss, night sweats, or blood in stool or urine to speak to their GP. Hormonal problems around the menopause can also contribute to tiredness.
Dr Khan advised: 'If rest doesn't fix it, don't just push through it. Ask your GP perhaps for a blood test, check your iron, B12, thyroid, maybe even do a stool test. And check your sleep quality.'
