While poison is the main suspect in the case, what are other ways a person could die of hypoxia?

Some people die cause of hypoxia, this usually happen due to insufficient oxygen available to the lungs. Like heart disease, stroke, if a person doesn't have enough blood in artery this may also result hypoxia. When the patients also posses a sickness like lung conditions, such as asthma and bronchitis this may also cause a sudden death and prone to hypoxia.