It's the latest mystery surrounding Hillary Clinton’s shocking collapse: Who is the woman by the Democratic presidential candidate’s side?

Read: 6-Year-Old Photographed with Hillary Clinton as She Left Chelsea's Apartment Says It Was 'Exciting'

Conspiracy theories are running wild on social media, with many suggesting she's a personal nurse.

One person posted: “Undercover nurse checking Hillary’s pulse?!”

“#Hillary squeezing her nurse's fingers. Clearly, she's disoriented,” wrote another.

There's also speculation the woman is Hillary’s personal doctor, Dr. Lisa Bardack.

But the Clinton Campaign is shooting down the rumors, telling Inside Edition the woman is a campaign aide, but they would not identify her by name.

After she collapsed, Hillary asked to be taken to Chelsea’s apartment to rest, a move that has been seen by some news outlets as a breach of protocol when she was not taken straight to an emergency room.

Clinton's critics say the former first lady and secretary of state was worried that word of her illness would leak.

Read: Hillary Clinton Says She Feels Fine and Didn't Faint at 9/11 Memorial Service: 'I Did Lose My Balance'

The Secret Service denies it violated protocol.

Watch: Did Hillary Clinton Use a Body Double After Falling Ill at 9/11 Memorial Appearance?