Congressman Raúl Grijalva, D-Ariz., announced Tuesday that he had been diagnosed with cancer. 

“A few weeks ago, I sought medical treatment for a persistent cough which was initially diagnosed as pneumonia," Grijalva said. "After further testing and imaging, my physician discovered that I have cancer.”

The 76-year-old lawmaker said that his congressional office will remain open and that he is in constant communication with his staff to get the work of his constituents done. 

“I am grateful to my family, friends and doctors for their support, and I am working hard to get healthy and return to business as usual as soon as I am able," Grijalva said. "I appreciate your consideration, well wishes and respect for my family’s privacy during this time. My heart goes out to others struggling with cancer, and I wish everyone strength in their fight.” 

It is unclear what kind of cancer Grijalva has been diagnosed with. 

Grijalva represents Arizona's seventh district and is the top Democrat of the House Natural Resources Committee.