If you’re mining from a desktop machine, there should not be any additional wear and tear from mining than there would be from gaming or any other activity as long as you properly care for it by following a few guidelines:

• The computer has proper airflow.  It’s not filled with cat hair (really, or dog or llama)
• It’s not overclocked or modified to do more than it should.
• Stays within the manufacturers' specifications or guidelines.

Based on guidance from hardware manufacturers, we do not recommend mining on laptops as they are more sensitive to heat and have less airflow.

As always, it’s a good idea to check manufacturers' guidelines and otherwise use common sense.