Teng died from a severe asthma attack, though doctors and her partner Paul Quilery had speculated that she died from a heart attack due to a side effect of an overdose of unspecified amphetamines while on holiday in Chiang Mai, Thailand at the age of 42 on 8 May 1995. Quilery was buying groceries when the attack occurred. He was aware that Teng relied on the same medication in the two months before her death with minor attacks. Teng had asthma throughout her adult life.