The biggest killer disease in 2017 isn’t going to be HIV. Not Ebola, either. Or Zika or pandemic influenza, or even drug-resistant tuberculosis. The disease that will kill the most people in 2017 will be a disease we hardly ever think about: heart disease, specifically ischemic heart disease.

The leading global cause of death in 2000 was ischemic heart disease (IHD). In 2012, it remained ischemic heart disease; more people died of the disease in 2012 than in 2000. The 2016 data isn’t processed yet, but all indicators point to the idea that it will be heart disease, once again. In fact; World Health Organization mortality estimates suggest that in 2030, the leading cause of death will still be ischemic heart disease.

Heart disease is a massive threat to human health, yet it garners very little attention.

The average person in any given country, wealthy or poor, is more likely to die of heart disease than any other cause. Somehow, however, heart disease doesn’t generate fear, perhaps because it is often seen as a natural consequence of aging, even when it strikes people who aren’t elderly. Media coverage for heart disease tends to be minimal.

Ischemic heart disease (IHD), also known as coronary artery disease, is a condition in which the flow of blood and oxygen to the heart is restricted. This happens when the arteries to the heart become stiff and narrow, reducing blood flow. Risk factors for the disease include high blood pressure, smoking, diabetes, lack of exercise, obesity, high cholesterol, excessive alcohol, and depression.

Heart disease used to be known as a disease of the rich. It caused deaths in wealthy countries, not the developing world. It turns out, though, that it’s not wealth that causes heart disease. It’s cities. As urbanization increases, heart disease increases along with it.

The link between urbanization and heart disease is complicated. The environment of a city contributes to heart disease through air and noise pollution. Air pollution has been linked directly to heart disease; noise pollution drives up blood pressure, contributing to heart disease.

Poorly designed cities that are unsafe for walking reduce exercise levels in their inhabitants. Sedentary lifestyles link to heart disease, and they link to obesity, which is a causal factor in heart disease.

Cities don’t have to be this way.

The UN released a urbanization report last year on ways to make cities healthy places. If public transportation and green space are good enough, cities can be a force for good health. Cities offer better access to health care than rural areas, for example. Right now, though, urbanization is creating traffic-filled, polluted megacities that make it difficult to lead a healthy life.

IHD can’t be cured in any traditional sense. There is no drug that will simply make it go away. Medications for reducing blood pressure help, but they treat a symptom. Unlike, for example, HIV drugs, they do not address the actual condition.

Broadly, IHD is caused by environmental factors but an individual patient can only improve their health through challenging lifestyle changes. To reduce their risk of dying from IHD, a person must change what they eat and how they live their day-to-day life. This is difficult for the wealthy; who struggle to enjoy unfamiliar foods and fit in time for workouts. It can be nearly impossible for poor people. If your job is spending 18 hours a day selling eggs on a street corner in heavy traffic, how can you increase your intake of green vegetables and get more exercise? In addition, no change in diet or increase in activity can eliminate air pollution.

As indicated by the WHO predictions, no one really thinks that the current approach to IHD is going to have much impact. Encouraging people to move more and eat better has a very limited effect when the environment supports neither movement nor the consumption of produce. If things stay as they are, IHD will be the leading killer in 2017, 2030, and probably 2050 as well.

Changing this future and reducing the rates of IHD would require coordinated action across multiple sectors. Improving peoples diets would involve ensuring that fresh produce was affordable and accessible and regulating the nutritional content and promotion of processes foods. Reducing traffic in order to improve walkability and air quality would require effective public transportation systems and taxes on fuel for private vehicles. Traffic reductions alone would not sufficiently clean the air in many cities; industrial emissions would also need to decrease. Creating green space to improve exercise levels will require land uses changes, and possibly even purchases of expensive center-city property. Finally, the best way to reduce smoking is through heavy taxation of tobacco and the passage of laws that restrict smoking.

This kind of multi-sector effort seems frankly unlikely. It would take major political will at a national level. Contagious epidemics like Ebola and Zika attract attention and generate the visceral fear that can actually lead to action. Heart disease doesn’t provoke that kind of emotional response in media, policymakers, or even patients. The odds of seeing major changes in the way that people experience city life are slim.

Instead, we will probably see a continuation of the status quo. Most cities and countries will continue to implement occasional single-sector efforts to improve health disease. Smoking in bars and restaurants will be banned in more cities. Public health campaigns will encourage exercise and healthy behavior. Public transportation will struggle for funding while new roads and bridges are built. Deaths from heart disease will be seen as the natural order of things, and remain much too common.