Loh was born in Ipoh, Malaysia of an ethnic Chinese family. She grew up in Singapore and completed a degree in Biology and Classics at Boston University in the United States. She then went on to study at the Boston University School of Medicine and undertook a residency in internal medicine. After a short stint in private practice, she quit her full-time medical job when she was awarded a full scholarship to the Master of Fine Arts program at Warren Wilson College in Creative Writing (Fiction). While pursuing her degree, she worked part-time as a physician; an aerobics and dance instructor; and personal trainer to support herself. She graduated in July 2001 and her novel Breaking the Tongue, written during her MFA program, was published in 2004. She is currently the medical director of the Earth and Sage Medical Spa in Newton, MA.