Oily skin resists the signs of ageing for longer, but excessive oil can impact skin health. Healthy microbes on your skin consume excess oil so these beneficial bacteria need to be nurtured. Genuinely oily skin tends to show slight thickening with open pores. Make-up does not hold well, and blackheads, blemishes and congestion are common. Many people think that their skin is oily, and therapists will often have a tough time in convincing a client that stripping their skin is not the best approach.