A survey recently released by market research firm Nielsen found 44 percent of respondents citing health as their key concern, followed by job security (42 percent) and work/life balance (22 percent).

Louise Hawley, managing director of Nielsen Vietnam, said: "Vietnamese consumers care about their health more than ever. Pollution in the air and in the environment is a hot topic increasingly top of mind for people."

Health would likely remain the top concern in the third quarter, she said.

Vietnamese consumers are not just worried about their health but are taking action to protect it. Vietnam was the country with the highest rate of people - 38 percent - saying their spare money goes to pay medical insurance premiums in Q2. It is followed by Switzerland (35 percent), Indonesia (35 percent) and China (33 percent).

Another concern was utility bills, which doubled from 6 percent in Q1 to 13 percent in Q2 when the government raised electricity tariffs by 8.36 percent in March after keeping it unchanged for two years.

Rising worries about utility bills make Vietnamese more reluctant to spend. Spending on new clothes fell by 9 percentage points from Q1, on gadgets by 8 percent and on holidays by 5 percent.

The Vietnam consumer confidence index score fell 6 points from Q1 to 123. The country fell from the third to fourth most optimistic country in the world behind India, the Philippines and Indonesia.