Cause
There are
different types of acne. The most common
acne is the type that develops during the teen years.
Puberty causes hormone levels to rise, especially
testosterone. High hormones cause signal skin glands
to start making more oil (sebum). Oil releases from the pores to protect the
skin and keep it moist. Acne begins when oil mixes with dead cells and clogs
the skin's pores. Bacteria can grow in this mixture, and if it leaks into
nearby tissues, it causes swelling, redness, and pus. A common name for these
raised bumps is
pimples.
See an illustration of
how
pimples form
.
Certain
medications can cause acne to develop. This type of
acne usually clears up when you stop taking the medication.
It isn't just teens who are
affected by acne. Sometimes newborns have acne because
their mothers pass hormones to them just before delivery. Acne can also appear
when the stress of birth causes the baby's body to release hormones on its own.
Young children and older adults also may get acne.
A few conditions of the
endocrine system, such as
polycystic ovary syndrome and
Cushing's syndrome, can lead to outbreaks of
acne.