There was little doubt in Alishia Hicks’s mind that her 17-year-old son was having a stroke as a staffer at the Henderson Upper School in Dorchester conveyed his symptoms to her over the phone: The staffer reported the teen was feeling light headed and the left side of his body was numb.

Hicks, who was in bed with the flu in her Mattapan home and who uses a wheelchair, told the staffer to call an ambulance and get her son to a hospital fast. She stressed there was a history of strokes in their family. But the staffer, she said, insisted an ambulance wasn’t necessary and that Hicks should pick him up herself. Someone at the school then reported Hicks to the state Department of Children and Families, according to the mother.

In the end, Hicks said, her son, who’s on the autism spectrum, was taken to Tufts Medical Center where it was determined he had a stroke and a medical team removed a blood clot from his brain.

Now, Hicks wants to know why the school contacted social services, while allegedly hedging on calling an ambulance.

She questions whether race was a factor, noting national research has shown racial bias in medical treatment. She and her son are Black.

“I was afraid for my son,” said Hicks, as she recalled the frantic phone calls with the school staffer while her son was in medical distress. “I kept telling her ‘Please get him to a hospital.’ She said he didn’t need an ambulance, that I should pick him up and take him to a doctor’s office. I’m in a wheelchair. I told her there is no time.”

A DCF worker reached out to Hicks at 2:39 p.m. to figure out what was going on, she said. After Hicks relayed the information to DCF, the school called back Hicks to say an ambulance had been called, Hicks said.

Roughly 45 minutes elapsed from the time the school first called Hicks at 1:59 p.m. on May 3 until the school informed her an ambulance was on the way, the mother said. It’s not known exactly when the school called an ambulance because the Boston Public Health Commission, which oversees Boston EMS, would not provide the Globe any information about ambulance calls to the Henderson on that day.

Her son initially was taken to nearby Carney Hospital, where the ER called Hicks at 3:24 p.m. to obtain her consent for medical care. After a round of testing, the teen was taken by another ambulance to Tufts.

DCF said in a statement it received a report and is investigating. The agency declined to provide additional details about the report or investigation — including the identity of who filed it — citing privacy laws.

Boston Public Schools said it is examining the school’s response.

“Our concern is first with the health and well-being of this student,” the school district said in a statement. “We hope for a full and speedy recovery. This serious incident is being reviewed by appropriate BPS staff and therefore it would be inappropriate to comment further on this specific matter.”

A growing body of research has revealed racial bias in medical care. Two studies released earlier this year, which examined hospital notes, found health care workers were more likely to describe Black patients in negative terms and other studies have shown medical professionals are less likely to treat Black patients for pain than white patients.

Meanwhile in Massachusetts, the Board of Registration in Medicine, which licenses doctors in this state, is requiring all doctors to take two hours of instruction in implicit bias in the areas of gender, race, ethnicity, and culture, starting next month.

A Boston schools spokesperson said the district already provides a professional education program on racial bias and equity in health as part of its “Nurse Opening Day” program at the start of the school year.

Hicks doesn’t know why her son suffered a stroke that day. According to his discharge paperwork, a portion of which was shared with the Globe, he was treated for an acute ischemic stroke. The doctors are still examining why he had a stroke, but preexisting medical conditions put him at risk, according to the document.

“I’m so grateful they were able to get the blockage out without causing any long-term damage,” the mother said.

Strokes in children and teenagers are considered rare, according to medical research. But stroke is one of the top 10 causes of death in children, according to Johns Hopkins Medicine. Signs of a stroke include numbness or weakness on one side of the body, slurred speech, trouble balancing or walking, vision problems, drowsiness, and seizures.

After spending two nights at Tufts, Hicks’s son, D’Andre, is resting comfortably at home.

In an interview Monday, the son said he is confused and disappointed by how the school responded. He said he could hear school staff argue with his mother during multiple phone calls between the two. He said he’s hesitant about returning to school.

“I just don’t know how to feel about it. ... They are good people,” he said of the school’s staff. “It was just the wrong way to deal with it.”

D’Andre said he first started feeling ill after lunch around 1:30 p.m. His heartbeat increasingly quickened as he walked up three flights of stairs from the cafeteria to his math class. He became dizzy and could feel numbness on the left side of his body. He struggled to walk up the stairs. Every time he stepped with his left foot, he said, he felt pins and needles, his left hand was numb, and it was difficult to lift his arm.

His math teacher, he said, “thought I looked off” and brought him to another room, where one of the school nurses came up to check his heart beat and blood pressure. The nurse, he said, then brought him to her office on another floor.

After the first phone call between his mother and a school staffer ended, he said, he overheard discussions about calling DCF. Confused, D’Andre said he called his mother on his cellphone to find out more about what was going on.

“I was trying my best to stay conscious,” he said. “I was afraid if I fell asleep, I would fall into a coma or die.”

The next day when his mother spoke to D’Andre by phone — she couldn’t visit him in the hospital because she had the flu — she said the first thing he said was, “I can’t believe they didn’t believe me.” Later that day, the mother said, Boston Schools Superintendent Brenda Cassellius called the mother and offered her “deepest apologies.”

The Great Divide team explores educational inequality in Boston and statewide. Sign up to receive our newsletter, and send ideas and tips to thegreatdivide@globe.com.

James Vaznis can be reached at james.vaznis@globe.com. Follow him on Twitter @globevaznis.

Work at Boston Globe Media