Need some help (written in English)

Hello! One of my students sent it to me:

If you have a cough, sneeze, headache, you catch a cold or flu. (This phrase is said by doctor who it telling to his patient what has happened with him)

I think that the second part is wrong. In my opinion, we need to use "you have caught a cold", but I can't find any proof that we can use the Present Perfect Tense in this case. Can you give me some comments about these two sentences?