Final answer:
Interest groups influence health policy through lobbying, electioneering, litigation, and shaping the issues through the media.
Step-by-step explanation:
Interest groups have influences on health policy through direct and indirect lobbying, electioneering, litigation, and shaping the issues through the media. They play a significant role in advocating for specific health policies and influencing lawmakers to support their positions. While interest groups can have a considerable impact on health policy, whether their influence is considered undue or not is subjective and dependent on various factors.