What are the differences between sun protection products?

I find choosing among all of the available sunscreens and sunblocks to be very confusing. Of the following three products I am currently using, which one is giving my skin the most protection: sunscreen SPF 30 with UVA, UVB, and IR sun protection; sunblock SPF 17 with UVA, UVB, and IR sun protection; or, sunblock SPF 50 with UVA and UVB sun protection? By the way, what is the difference between a sunSCREEN and a sunBLOCK?


What are the risks of gel and shellac nail manicures?

I love getting my nails done with a gel or shellac manicure. The polish doesn't chip at all and stays shiny for weeks. I'm just worried about the UV light used to seal the manicure - it is almost like a mini tanning bed for your hands. What are the risks? And are there any bad chemicals in the polish?


Are moles that change color or increase in number a cause for concern?

1) Over the span of the last couple of years, I have noticed a significant number of moles appearing on my body. They have been appearing everywhere from my neck to my inner thighs. I had one on my neck since childhood, but now have so many more. Is this normal? Is it something I should be concerned with? And does child bearing have any relevance to this happening?

2) I have a mole which has turned very dark purple, and grown a bit in size (still small). This is the second time it has done this — last time was a couple of weeks ago, and it slowly faded back to almost nothing until today. Should I be very concerned about this?