Shane Gromley pulled an all-nighter on Monday because he was studying for a Tuesday-morning pharmacology test.

Gromley, a sophomore nursing major, isn’t the only college student who loses significant sleep and who — between class, homework, jobs and other commitments — believes there aren’t enough hours in the day.

Psychology professor Douglas Delahanty said sleep deprivation and stress often work together to hurt college students’ health.

“Stress increases every negative health behavior; it decreases every positive health behavior…” he said. “One reason stress might be bad is because of sleep deprivation. You don’t have that recuperation time.”

What you might not know about sleep deprivation:

1. You’re still supposed to get eight hours of sleep a night. However, only about 30 percent of college students actually get this much sleep per night.

2. When you don’t sleep, you create a “sleep debt.” This debt affects mood and productivity, according to the Stanford University Center of Excellence for the Diagnosis and Treatment of Sleep Disorders. The only way to reduce sleep debt is to get more sleep than the daily requirement.

3. Loss of sleep weakens the body’s immune system, Delahanty said, and research on animals has shown that sleep deprivation can result in illness and death. However, research hasn’t proven that sleep deprivation is terminal for humans.

4. Sleep deprivation also makes it difficult to maintain body heat, Delahanty said, and students might feel colder than normal the day after an all-nighter.

5. ABC News reported stroke, obesity, diabetes, anxiety, depression, cancer and heart disease as possible long-term health hazards linked to lack of sleep.

6. A study by a Harvard Medical School professor showed that pulling all-nighters creates a euphoric feeling the next day, which can encourage addiction and impulse behavior. It also harms memory and puts students at risk for long-term brain damage.

Multiple nights without sleep:

Day 1 or 2:

After 24 hours of no sleep, the body begins to experience detrimental changes — like rising levels of stress hormones, which increase blood pressure levels, according to researchers at Harvard Medical School. The body decreases its ability to properly metabolize glucose, the immune system stops working as well and the body’s internal temperature begins to sink.

Days 3 through 11:

The longest a human has been able to stay awake is 264 hours, which is 11 days. A 42-year-old man named Tony Wright broke the record in 2007, Discovery Fit & Health reported. After three days without sleep, individuals show significant deficits in concentration, motivation and perception, according to J. Christian Gillin, a professor of psychiatry at the University of California, San Diego. Other reports include hallucinations and mania.

More than 11 days:

In June, a 26-year-old man in China died after 11 days without sleep. Research hasn’t proved that sleep deprivation causes death in humans, but it significantly weakens the immune system. Long term, too little sleep can promote calcium buildup in the heart arteries, which can lead to heart attacks and strokes, according to researchers at the University of Chicago.

Contact Alyssa Morlacci at [email protected].