1. He's nervous.
"The pressure of wanting to get hard, stay hard, and satisfy your partner can make it difficult to get hard in the first place," says Dr. Jane Greer, New York-based marriage and sex therapist and author of What About Me? Stop Selfishness From Ruining Your Relationship. In cases like these, it's as simple as taking your time and letting his sex drive kick into high gear. Remind him that his penis is beautiful and special.
2. He's drunk.
Drinking delays reactions and mutes nerves, so his penis won't get excited the way it's supposed to. It might make him have trouble achieving orgasm or he might get the dreaded "whiskey dick," when he just plain can't get hard. Alcohol is a depressant, and when his penis gets sad, it doesn't want to get out of bed.
3. He's overweight.
Excess weight causes circulation problems and damages the blood vessels, so blood has a harder time getting to the penis to keep it hard. All the more incentive to start working out together.
4. He actually has a physiological problem.
Heart disease, diabetes, multiple sclerosis: Any of these, among other diseases, can block the nerve impulses that get him aroused. There is medication to help some of these conditions, but your guy should be open with you about any boner-affecting illnesses he has.
5. He smokes.
"Smoking can impact circulation and constrict the blood vessels. You need blood flow for an erection," says Greer. Also, just, boo smoking.
6. He has low testosterone.
Testosterone levels naturally drop off with age, causing guys to grow less body hair and have trouble getting erections, among other things. Luckily, this one can be easily fixed with supplements.
7. He's on some sort of medication.
Prescription drugs are physiological wild cards, like Olivia Pope in pill form. She's fixing everything, sure, but she's also messing up her own life and having an affair with the President. "Depending on the medication that you're taking, if they impact testosterone level they can lower your sex drive," says Greer. "They can also affect energy level and make you drowsy or make you gain weight. That can impact your emotional and physical energy."
8. He's stressed.
Unpaid bills, a douchey boss, or relationship problems can also make it tough for a guy to get hard. "That's the nature of anxiety: 'Uh oh! What if?'" says Greer. "Men can have these 'what if' moments that are compounding the real issue. Even after the main problem is discovered and corrected, it may take some time to get back to business as usual."
This article originally appeared on Cosmopolitan.com. Minor changes have been implemented by Cosmo.ph editors.