Doctor, doctor: On nasal piercings and fingernails

How long would my fingernails get if I didn't cut them?
Valerie Jamieson of the New Scientist wrote in 2005 about the work of Dr William Bennett Bean. When he was 32, he made a horizontal line on his left thumbnail, then timed how long it took to reach the end of his finger – he could then work out how fast the nail was growing. And he did this for 35 years. When he was young, the nail grew at 0.123mm a day; by the time he was 67, its growth rate had slowed to 0.095mm a day. Unfortunately, we have the figures for the thumb only, and not for the other fingers or toes. The likelihood is that the nails on your thumbs and your big toes grow faster than those on the other digits, because they enjoy a brisker and more plentiful blood supply. So, to answer your question, if you were to grow them over a lifetime, your nails would be 2m long, though they would be curved and coiled, not straight. Incidentally, hair grows at about 10 times the rate of nails.

I am a healthy 17-year-old girl, who wants to get her nostril pierced. My mum is worried about its high risk of infection. Can it really cause any significant damage, or can she put her mind at rest?
Your mum is right. The piercing goes through the more delicate skin inside the nose, and as a result this can cause more infections than, say, an ear piercing. And if it does become infected, it can lead to scarring and a permanent deformity in the skin of the nostril, which is a lot more obvious, of course, than an infected ear lobe, for example. Remember, too, that if, one day, you wish to remove your piercing from your nose, it will leave a hole that will be more obvious than a similar hole in the ear. Added to which, you will inevitably have colds in the future, and if you have a nasal piercing this can produce dribbling of mucus and discomfort in the nose – again, something that doesn't happen in ear piercing. A rarer complication is an allergy to the metal in the stud – this is most likely with one containing nickel – and it can produce a red, raw swelling that can be itchy and painful. In short, this isn't a decision you should take lightly.

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