Why is WhatsApp taking up so much internal memory?

A

AC Question

Yesterday, I found out that WhatsApp is taking 6,50 GB of my internal memory (Huawei Ascend P7). In my settings>memory>apps>whatsapp, it shows that the app itself is 24,59 MB, while the app data takes up 6,48 GB. Does anyone know why? And how I can reduce this without reinstalling the entire application?