Dengue is a hemorrhagic fever and can be quite serious, especially in the very young and the very old. There is no vaccine for it, so you should try your best to avoid mosquito bites, especially during the day time – as the particular species that carries the disease is active in the day.
Dengue is marked by fever and pain in the joints as well as the appearance of blood depending on the organs in which it settles; for instance, some people may show blood in their urine if the bladder or kidneys are affected.