Stretch marks (known medically as striae) happen when the skin stretches rapidly, causing the underlying collagen and elastin fibres to tear. It’s very common for this to happen during pregnancy, but it can also happen during growth spurts, weight changes or muscle building. Stretch marks tend to show as streaks on the abdomen, thighs, hips, breasts or arms. At first, they usually appear red, purple or dark brown, but they often fade to pale lines over time.

Many people feel self-conscious about stretch marks, particularly if they’re large, or are in visible areas. It’s worth knowing that they’re incredibly common – most people have them somewhere – but most people would probably prefer them not to be there. It’s also important to know that they are harmless, and are a natural part of your skin’s healing process.