According to the third National Survey of Sexual Attitudes and Lifestyles (Natsal), published in 2013, both men and women in the UK report having sex about five times a month.

The survey also found that older people are having sex well into later life and young people are having sex earlier. However, the overall results show that people are having sex less often than they were 20 years ago.

Research suggests a woman's outlook on sex is more complicated than a man's. Men tend to have specific and set views about what arouses them. Women tend to have less rigid views of their sex drives. Studies show women are more likely to call themselves bisexual and are less set in their ways regarding sex. Overall their attitudes are more "fluid" but they are also more heavily influenced by social and cultural factors, such as the attitudes of family or friends.

When erect, the average penis length is between 14–16 cm (5.5 to 6.3 inches). The average girth for an erect penis is 12-13 cm (4.7–5.1 inches).

The measurements are based on a review of over 11,000 penises in 50 studies conducted over the last 70 years.

Men tend to reach orgasm when vaginal intercourse is involved. Women may reach orgasm when they engage in a variety of sex activities - and when oral sex or vaginal intercourse is included. In one survey of men and women, 10% of men and 18% of women reported a preference for oral sex to achieve orgasm.

According to a study published in the Journal of Sexual Medicine, the average time it takes for a man to ejaculate during sexual intercourse is 5.4 minutes.

Psychological stress can have the same effect on an erect penis as cold water. It can make your penis shrink, if only temporarily. Environmental factors like cold air can have this effect. Other culprits include excess alcohol, fatigue or illegal drugs. However, non-physical causes, like stress, anxiety or depression can also trigger erection difficulties. In some cases, psychological issues can lead to longer term erectile dysfunction.

The National Survey of Sexual Attitudes and Lifestyles revealed a shift in British attitudes towards one night stands and adultery. British women who were surveyed were more accepting of one night stands outside an exclusive relationship. However 63% of men and 70% of women disapproved of people who cheat on their marriage partners.

For the most part, researchers agree masturbation is healthy and safe. Knowing how your own body responds sexually helps you understand what arouses you and helps inform your partner about what feels good for you.

However, going solo can trigger dysfunction if it becomes obsessive and causes you to lose interest in your partner. It is also possible for masturbation to cause harm if it is too vigorous or too frequent. This can result in irritation. Also, men who masturbate face-down can injure their urethras.

Research suggests that men under the age of 60 think about sex at least once a day. Only a quarter of women in the same age group think about sex that often. Both men and women fantasize less about sex as they age, but men still have wandering minds twice as often as women.

Researchers in one study found that 29% of women who were part of a couple reported always having an orgasm with their partner.

Research conducted by The Sexual Advice Association found half of women have sexual problems – including problems achieving orgasm. Problems were also more common as the women aged. If you're experiencing orgasm difficulty see your GP, or visit a genitourinary medicine (GUM) clinic, for a checkup on what may be causing the issue.

The majority of women need direct stimulation of the clitoris to have an orgasm. Often just adding this kind of stimulation during sex can help women who are having problems with orgasm.

The G-spot – or Grafenberg Spot – is the subject of hot debate. The G-spot was made popular by a 1982 book but there is doubt over whether it actually exists or not. A 2009 British study concluded its existence was unproven and subjective. Some experts suggest, if the G-spot does exist, it may be better described as an erogenous zone, rather than a distinct part of the female anatomy.

Certainly, older people with a history of heart disease should check with their GP about any risk during sexual activity but, overall, sex is a healthy form of exercise as we age. A 20 year study of 914 men concluded having sex twice or more a week actually halved their risk of heart attack, compared to men who had sex once a month. The same study found frequency of sex was not linked with strokes.