More than 30 percent of 14 million Asian Americans -- most of whom are foreign born - are weak in English, making them less likely to understand explanations of medical procedures and medication instructions, officials said.
They also risk losing equal access to voting rights and education and other government services because of the language barrier.
"I have heard many stories of failed access to services because of language issues," said US House of Representatives lawmaker Mike Honda, who has introduced legislation with bipartisan support aimed at honing English language skills of immigrants.
An ethnic Hmong from Southeast Asia "had the wrong leg amputated in a surgery," he said.
"Because no translators were provided, the man's son was left with no choice but to try to interpret the consent form himself, and it was sadly misinterpreted," said Honda, who represents a district in California with one of the largest Asian populations.
The Japanese-American lawmaker cited another case, of a Lao woman suffering from tuberculosis who was "imprisoned for not taking her medications.
"Her English proficiency was limited, and the necessity of taking her medication was never explained to her. Thankfully, she filed a lawsuit for wrongful imprisonment and won," Honda said.
"These stories are not uncommon to Asian American and Pacific islanders and other minority communities. In fact, as appalling as these seem, many of our families face this reality daily," he said.
The legislation introduced by Honda and Republican lawmaker Cuban-born Ileana Ros-Lehtinen supports English literacy and civics education, ensures that schools have adequate funding for literacy programs for English language learners and creates tax incentives for employers who offer adult education and English as a second language program to their employees.
Although the bill is aimed at all immigrants, Asian American Justice Center President Karen Narasaki said the benefits "will be immense" for the Asian American community, which has a high percentage of English learners.
"More than a third of our population is limited in English proficiency and a majority are foreign-born," she said.
Asian Americans are also the most "linguistically isolated" racial groups in the United States, studies show.
About 22 percent of adults who spoke an Asian language spoke English not well or not at all, according to the 2000 Census. The percentage of seniors 65 and older in that category was 51 percent.
Among households where an Asian language is primary, 30 percent was considered to be linguistically isolated compared to 26 percent for Spanish-speaking households.
When disaggregated, the percentages are even greater among Southeast Asian groups -- 45 percent of Vietnamese Americans, 31.8 percent of Cambodian and Laotian Americans, and 35.1 percent of Hmong Americans were linguistically isolated.
Asian American groups are waging public education campaigns, including informing the community that they could be adept at retaining their culture while at the same time being proficient in English.
"At a time when language is a proxy for culture, we emphasize that learning English does not come at the expense of our identity or heritage," said AsianWeek, a San Francisco publication, in a recent editorial.
"We consider ourselves 100 percent American in our English proficiency and still consider ourselves 100 percent Asian American as we celebrate and draw upon our heritage," it said.