You get enough sleep and don't stay up late, but you still feel tired every morning. Experts say the cause could be a sleep cycle disorder, blood sugar issues, or sleep apnea.
According to Dr. Chau Thi Anh, a specialist at Xuyen A General Hospital in Ho Chi Minh City, feeling tired even after getting enough sleep (about 8 hours) is often a sign that your sleep quality or metabolic state is problematic. You should consider the following factors:
Disruptions to the circadian rhythm and sleep cycle.
A standard sleep cycle consists of several cycles, each lasting approximately 90 minutes. If you wake up during the deep sleep stage, your body enters a state of "sleep inertia," causing prolonged lethargy and fatigue.
So, the cause of fatigue could be that you are lacking deep sleep or REM sleep – the two most important stages for brain and muscle recovery.
Even with sufficient sleep, feeling tired is often a sign that there are problems with sleep quality or your body's metabolism.
ILLUSTRATIVE PHOTO: Created by Le Cam using Gemini
Blood sugar instability
This aspect is closely related to nutrition. If dinner has a very high glycemic index (GI), insulin levels spike and then drop abruptly during the night.
Nocturnal hypoglycemia causes the body to release stress hormones (like cortisol) to raise blood sugar, resulting in disrupted sleep even though you don't wake up. Therefore, it's important to carefully control high GI (glycemic index) foods in the evening to maintain stable energy levels throughout the night.
Sleep apnea syndrome
Sleep apnea is often overlooked. When the airways narrow, the oxygen levels in the blood drop, forcing the brain to "wake up" to breathe (even if you don't remember anything the next morning). This is often accompanied by headaches, dry mouth, or a sore throat. In the long term, this puts significant strain on the cardiovascular system.
Problems with circulation and toxin elimination.
If the venous and circulatory systems are not working efficiently, metabolic byproducts (lactic acid, free radicals) are not properly eliminated from the muscles overnight.
Warning: A feeling of heaviness in the legs or muscle fatigue immediately upon waking. This is sometimes related to impaired blood circulation in the lower extremities.
"Mental fatigue"
Sometimes the body isn't tired, but the mind is overloaded with unresolved anxieties. From a practical philosophy perspective, allowing the mind to "wander" too much into uncontrollable thoughts consumes more energy than physical activity. This signals that you are experiencing a state of nervous exhaustion (burnout).
Quick check steps:
- Do you remember if you often snored loudly or felt short of breath while sleeping?
- Check for micronutrient deficiencies, as magnesium, iron (anemia), or vitamin D deficiencies are also leading causes of chronic fatigue.
- Do you use electronic devices close to bedtime? Blue light inhibits melatonin, reducing the quality of cell repair.
"If you're still tired despite getting enough sleep for more than two weeks, even after adjusting your diet (low GI, sufficient protein), you should consider getting some basic blood tests and cardiovascular screening to determine the exact cause," the doctor advised.