Ebola diseases symptoms can be sudden. They include fever, fatigue, muscle, pain, headache and sore throat. This is followed by vomiting, diarrhoea, rash, symptoms of impaired kidney and liver function, and in some cases internal and external bleeding (e.g., oozing from the gums, blood in the stool). Laboratory findings include low white blood cell and platelet counts and elevated liver enzymes.

It can be difficult to clinically distinguish Ebola diseases symptoms from other infectious diseases such as malaria, typhoid fever and meningitis. A range of diagnostic tests have been developed to confirm the presence of the virus.

The incubation period, that is, the time interval from infection with the virus to onset of symptoms, is from 2 to 21 days. A person infected with an Ebolavirus cannot spread the disease until they develop symptoms.

Supportive care—rehydration with oral or intravenous fluids—and treatment of specific symptoms improves survival. A range of potential treatments including blood products, immune therapies and drug therapies are currently being evaluated.

During the 2018–2020 Ebola virus disease (EVD) outbreak caused by Zaire ebolavirus in the Democratic Republic of the Congo, the first-ever multi-drug randomized control trial was conducted to evaluate the effectiveness and safety of drugs used in the treatment of EVD patients under an ethical framework developed in consultation with experts in the field and the DRC.

Two monoclonal antibodies (Inmazeb and Ebanga) were approved for the treatment of Zaire ebolavirus infection in adults and children by the US Food and Drug Administration in late 2020.