Question: If cancer cells are just super healthy how/why do they make us so ill?

Andrew Devitt answered on 24 Jun 2013:

That’s a really great question! They are healthy cells in the sense that they grow well and don’t die easily. But in our bodies, if they grow too much then they start to interfere with the normal function of our organs. So I guess they aren’t really good ‘team’ players – they look after themselves and don’t care about the rest of you.

So if a tumour grows in your lungs, it will stop your lungs functioning well (and I don’t need to tell you that ain’t good). Same deal with kidneys and liver….

Tumours can also cause blockages (like in your guts) and that also creates problems.

However cancer cells can also cause you to waste away and we don’t fully understand how this happens. People will often look really thin and frail when they have cancer. This is because they lose muscle – it seems to melt away. You get tired and lose your appetite. This is called cachexia (car-kex-eee-arr). This is can be a really bad sign and it is often seen in the later stages of the disease