SUNDAY, Feb. 2, 2020 (HealthDay News) -- Fighting the flu can be an unpleasant experience -- but the misery may not stop there.

When you have the flu, your immune system is under attack, making complications common. Other infections can weasel their way into your body, according to Libby Richards, an associate professor at Purdue University's School of Nursing in West Lafayette, Ind.

Common complications include pneumonia, sinus infections, ear infections and bronchitis.

"Pneumonia can occur as a secondary bacterial infection and occurs after you have had flu symptoms for several days," Richards said in a university news release. "It can also occur as a viral infection, which develops more rapidly."

Pneumonia is often accompanied by flu-like symptoms, including chills, fever and aches. Severe symptoms include shortness of breath, chest pains, sweating, high heart rate and a nasty cough. Signs of ear or sinus infections include facial pressure, drainage and ear pain.

If think you're experiencing flu complications, Richards urges you to see your doctor. You may need additional treatment, such as antibiotics, to fight off infection.

"Vaccination is the best way to reduce your chance of having complications from the flu," she said. "Second to vaccination, working to maintain a healthy immune system can help fight off complications."

The U.S. Centers for Disease Control and Prevention notes that rates of influenza and influenza-like illnesses are currently high throughout the country. An estimated 15 million cases have been diagnosed and 8,200 Americans have died due to influenza this season.

More information

The U.S. Centers for Disease Control and Prevention has more on flu symptoms and complications.