Conventional wisdom holds that men are simple creatures, whose needs and desires can be handily pegged. There's just one catch: Guys often prefer to keep quiet about their health concerns and problems. To promote better communication (and better health), it's important to encourage the men in your life to open up, but don't be surprised if they're reluctant to share the following seven secrets.

1. I'm in pain.

According to a 2001 report released by the Centers for Disease Control and Prevention (CDC), men are half as likely as women to go to the doctor for preventive-care visits. And additional evidence shows that even when they sense that something might be wrong with them, fear and embarrassment often stop them from seeking medical attention. A 2007 Harris Interactive poll found that 92 percent of men wait at least a few days to see if they feel better first. Unfortunately, nearly 30 percent of men take procrastination to the extreme, waiting "as long as possible" before seeking treatment.

2. I'm stressed out.

With a failing economy, an energy crisis, and global warming looming, it's no wonder that both men and women are feeling a bit frazzled these days. But a Canadian study found that women report these feelings of stress more often than men do. The problem is, harboring unhealthy amounts of tension can lead to back pain, ulcers, and-most especially for men-heart disease.

3. I have erectile dysfunction.

According to the National Institutes of Health (NIH), 15 to 30 million men in the United States will experience erectile dysfunction (ED) at some point in their lives. The good news? With the popularity of new medications and the understanding that ED can have both physical and emotional causes, men have become increasingly more open to talking about this problem.

4. I'm depressed.

Data from the NIH puts the number of American men suffering from a depressive disorder at about 6 million. Experts claim that guys are usually more willing to admit symptoms of fatigue and loss of interest in activities they once enjoyed than they are to acknowledge feelings of sadness or guilt.

5. I'm losing my hair.

It's a condition that many men can quite literally keep under their hats. About 35 million American men have androgenetic alopecia, also known as male pattern baldness, which can be passed down through the mother's or father's genes and can start anytime after puberty, when the level of androgen in the bloodstream rises.

6. I don't like the way I look.

A quarter of the male population in the United States is on a diet at any given time. And of the 8 million Americans who suffer from eating and body-image disorders, 1 million of them are men, according to the CDC. Another growing concern among health professionals: the increase in incidences of muscle dysmorphia, in which a person is consumed by the fear of having a petite, underdeveloped build and therefore compensates by exercising excessively or taking muscle enhancers such as steroids.

7. I'm scared.

A Dutch study conducted in 2005 found that in the face of a fear-inducing scenario, men reacted less emotionally than women did. When feelings of fear get out of control, as it does in an anxiety disorder such as social phobia, guys may be more likely to self-medicate with alcohol or drugs.