So what exactly causes large pores? Dermatologists have studied several factors, and there are three main causes: oily skin, age and sex [source: British Journal of Dermatology].
Our bodies produce sebum, an oily substance we secrete to make the skin waterproof and to keep it from drying out. People who have naturally oily skin tend to have larger pores. This happens because when oil and dirt collect in your skin, your skin swells and your pores look larger than they normally would. Some people may also associate large pores with severe acne, but this isn't always the case. Even though people with oily skin tend to be prone to acne, that doesn't mean acne is a secondary factor in the appearance of large pores. One reason for the misconception may be that small divots formed by acne scarring may look like enlarged pores.
Another contributing factor is age. As you get older your skin loses its elasticity, which can cause your pores to look bigger. Sun damage, which typically accumulates with age -- the older you are, the more you've been exposed to the sun -- also affects the appearance of pores. It makes your skin thicken, causing skin cells to collect around the edges of your pores, which stretch them out.
The third main factor is sex. In general, males tend to have larger pores than females. Women might experience enlarged pores more often during hormonal changes, however, particularly during menstruation.
Genetic predisposition may also be a contributing factor when it comes to pore size. If one or both of your parents have large pores, you might also have or eventually experience a similar condition.
Since several of the factors that contribute to larger pores can't be changed, you may be wondering whether you can do anything about them. Read on to learn how you can help create the illusion of smooth skin.