First things first, let's make one thing clear: sleep will not directly cause or completely heal your acne. What sleep (or the lack thereof) can do is affect the inflammation, the healing time and the severity of preexisting skin issues.
(They don't call it "beauty sleep" for nothing!)
The connection between sleep and acne is a multifaceted one. Firstly, poor sleeping habits are linked to elevated overall stress levels. According to one study, 45% of adults with already high stress levels reported feeling even more stressed due to lack of sleep. If you are one of those people who woke up with a giant zit during finals week, the link between stress and acne is clear.
When stressed, your body increases its production of glucocorticoids (which causes irregularities in skin function) and sebum (which can result in clogged pores). Thus, leaving acne-prone individuals with a higher chance of breaking when stressed and sleepy.
Additionally, a lack of sleep causes the body to release more cortisol, a pesky little stress hormone. When there is too much cortisol in your system, it worsens inflammation and starts breaking down collagen. Collagen is the protein that keeps your skin plump and smooth--and is especially important in healing leftover acne scars. Along those lines, human growth hormone levels are decreased due to poor sleep, which can affect skin tissue repair.
Also, there is increased blood flow to the skin while we slumber, which is why we wake up fresh and glowing after a full eight hours versus colorless and dull after sleepless nights.
Finally, poor sleep (along with poor diet and lack of exercise) is linked to exacerbating preexisting hormone imbalances--a very common cause of acne. We've already discussed how chronic sleep loss affects the stress hormone cortisol, but that isn't the only hormone affected. In fact, the secretion of several other hormones is affected as well. When your body's hormones are out-of-whack, your skin can suffer.
So, will changing your bedtime routine help your acne? There is a very good chance it will, especially if you are someone who struggles to get eight hours a night or who deals with a lot of stress. At the very least, a good night's rest will help improve your skin's overall glow and healing processes and (more importantly) your mood!
Oh, and one final tip: if you have acne, be sure to change your pillowcase often! Pillowcases house all sorts of dirt, oil and griminess that can clog up your pores.