Kseniya Ovchinnikova / Getty Images
It seems simple.
When you feel tired, it’s crucial that you sleep.
However, other signs that it’s crucial that you get more rest may be less clear.

Kseniya Ovchinnikova / Getty Images
Dark Circles
The skin around your eyes is the thinnest and most fragile on your body.
Muscle Aches
If you have mysterious aches and pains, it could be that you’re lacking sleep.
Stress can do it, too.
You may take longer to do familiar tasks, you make more mistakes, your reaction time is slowed.
Actions like driving can be more hazardous, and you may act more impulsively.
Cognitive functions like learning, memory, and attention are not as sharp.
Motor skills can also be affected.
Low Motivation
Sleep deprivationcan affect brain circuitry involved in how much you value the amount of effort you make.
If you’re sleep-deprived, an extra push may not feel worth it.
Your eyesight may be blurred because your eyes are too tired to make rapid adjustments.
Eye twitches can be another sign of too-tired eyes, which may feel more sensitive to light.
Memory Lapses
Your brain needs rest to file away all that’s happened each day for future reference.
Weight Gain
Sleep deprivation can cause you to confuse tiredness with hunger.
Sleep is also important to balance hormones that are connected to hunger.
If you’re rested, you may have moreleptin, which is associated with feeling full.
Moodiness and Feeling Irritated
Sleep and mood are closely related.
If you’re tired, you are more likely to become irritated.
Tired people often respond more strongly to stressful situations and have fewer positive reactions to daily experiences.
Anxiety and mood disorders can also cause insomnia, creating a vicious cycle.
If you are experiencing anxiety or feel withdrawn or sad, consider how well you’ve been sleeping.
Sleep deprivation can have a complicated effect on your libidothe desire for sex.
Some of it is psychological, and some is physiological.
It may also lead to greater dissatisfaction with sexual activity in women.
Women who get enough sleep may notice an increase in both the desire for sex and physical arousal.
When you sleep, the blood flow to your skin increases, which helps repair and prevent skin damage.
Your immune system needs sleep to function well.
There are many signs that you’re not getting enough sleep besides feeling simply tired.
National Institute of Neurological Disorders and Stroke.Brain basics: understanding sleep.
My Vision.org.Dark circles under the eyes: causes, treatment & prevention.
2015;40(1):17-22. doi:https:10.1111/ced.12455
MedlinePlus.Fatigue.
American Heart Association.What happens when we sleep, and why we need the right amount of it each night.
Elsevier; 2019:1-26. doi:10.1016/bs.pbr.2019.03.007
American Academy of Sleep Medicine.How lack of sleep affects your eyesight.
NIH News in Health.Sleep on it.
2019;39(5):888-899. doi:10.1523/JNEUROSCI.0250-18.2018
Sleep Foundation.Sleep and weight loss.
Harvard Medical School Division of Sleep Medicine.Sleep and mood.
Columbia University Dept of Psychiatry.How sleep deprivation impacts mental health.
NHS Inform.Loss of libido.
Costa R, Costa D, Pestana J.Subjective sleep quality, unstimulated sexual arousal, and sexual frequency.Sleep Science.
2015;12(5):1221-1232. doi:10.1111/jsm.12858
Mass General Brigham.Sleep and heart health.
Kreher JB.Diagnosis and prevention of overtraining syndrome: an opinion on education strategies.Open Access J Sports Med.
2016;7:115-22. doi:10.2147/OAJSM.S91657
Mental Health Foundation.Generalized anxiety disorder.
NIH Research Matters.Compound produced by bacteria protects the skin.
2024;16(Suppl 2):S1326-S1329.