Blood clots are gel-like clumps of blood, usually formed as a response to an injury, but can form within blood vessels, which can block the flow of blood and require medical attention. Throughout 2013, On Cinema host Tim Heidecker suffered a medical condition in which he allegedly suffered from blood clots in his brain, though the exact ailment is debated.

During the first week of February 2013, Tim was diagnosed with blood clots in his brain, a total of six.^[1] Tim and his wife Stephanie, for various reasons, were decided against getting surgery for the issue, stating that it was just one of several possible treatments suggested by his doctor. Tim and Stephanie felt that the surgery was “barbaric,”^[2] instead choosing to pursue alternative medicine, and refusing to get a second opinion. Guest Gregg Turkington insisted that Tim get the surgery, and theorized that this issue could potentially be brain tumors.

By April 2013, the number of clots had doubled to 12. Heidecker believed that the opportunity to get the surgery had passed, and was emotionally distraught as the other potential treatments presumably had not shown success, feeling that he would soon pass away from the clots.^[2][3]

In July 2013, Tim revealed that he did get a second opinion, despite Stephanie's wishes, and found that surgery was still a viable option to save his life. The conflict over if Tim should go through with the surgery lead to Tim and Stephanie divorcing, allowing Tim to finally get the operation.

Following the surgery, Tim was told to not do anything for two weeks. Despite this, Tim still filmed an episode of On Cinema at the Cinema, head bandaged, a week after the surgery. The exertion caused pain and headaches, which Tim treated with herbal supplements.^[3] Following the surgery, Tim wore hats for several weeks to cover his scar while he healed.^[4][5] The scar was on the left side of his head, which prevented him from sleeping for a period of time, as his normal sleeping position irritated the wound.^[5] A month after the surgery, he still felt like he needed an additional month to recover fully.^[6] He had to make frequent visits to the doctor, every two days, where his blood and spinal fluid was tested.^[7] By January 2014, Tim was fully cleared by the doctors.^[8]

As a side effect of the surgery, Tim was unable to physically laugh for a period of time.^[6]