Well, they are present perfect (have had) and past perfect (had had). As a conclusion you must see the difference between these two verb tenses.
Past Perfect- used to talk about past of past; you did something before another.
Ex: By the time I bought my car,I had (already) bought my house.
Resent Perfect: when you make something in the past and it is still having any effect.
Ex: I have eatten an apple. (I ate it but it's still inside of me)
Obs: sorry for any grammar mistake.