Dr Amir Khan has shared a TikTok video explaining the difference between being 'busy tired' and 'medically tired', stressing that knowing the distinction could be vital for your health. He said: "Are you feeling tired all the time? Well, you're not lazy. You're not just getting old. But there is a difference between being 'busy tired' and being 'medically tired', and knowing that difference can literally change your life."
Busy Tired vs Medically Tired
Dr Khan, who often appears on ITV offering health advice, said that tiredness from long days, late nights, stress, or Netflix binges usually improves after a good night's sleep or a weekend of rest. He said: "That's your body saying 'thanks, I'm fine now'."
However, if you are constantly exhausted even after quality sleep, or wake up feeling tired, foggy, unable to concentrate, or needing caffeine just to survive, he said that might be something to look into. He added: "Now, it could be something medical, so let me explain a few common ones."
Common Medical Causes
The first possible cause he highlighted is anaemia. "That's when you have a low red blood cell count," he said. "There's lots of different types of anaemia. Low iron is a common one. It means less oxygen is reaching your cells. You feel weak, dizzy and short of breath climbing stairs, for example."
The second potential culprit is low Vitamin D levels, which can be particularly problematic in the UK during the darker winter months. Dr Khan said: "Low Vitamin D can leave you feeling constantly tired, achy and low in mood. It's really common, so make sure you're taking your Vitamin D supplement."
Thyroid, Sleep Apnoea and Mental Health
Thyroid issues are another possible explanation. "If your thyroid's underactive, everything slows down. Your energy, your mood, even your digestion," Dr Khan said.
Sleep apnoea, where breathing repeatedly stops during sleep, also features on his list. "You might be sleeping, but your oxygen levels drop overnight," he said. "You wake up unrefreshed and can't figure out why. Normally we see it with people who are overweight, snoring, and their partner says they hear them stop breathing and then start again during the night."
Daytime exhaustion can also be triggered by depression and low mood. "Mental health fatigue is real. It's that heavy tiredness that doesn't shift even when life feels calm," Dr Khan said.
When to See a GP
He noted that more serious conditions, such as cancer, could occasionally be responsible, though he stressed such cases are uncommon. He urged anyone with persistent tiredness alongside unexplained weight loss, night sweats, or blood in your poo or urine to consult their GP. He also mentioned hormonal problems around the menopause as a possible cause.
Rounding off his advice, Dr Khan said: "So, 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." He added: "You deserve energy that lasts longer than your morning coffee. So are you busy tired, or medically tired? If you're not sure, get it checked. Your body is trying to tell you something."
