Just as you seek the best medical treatment to avoid illnesses and improve your physical health and wellbeing, whether that be paracetamol to treat a mere headache or something more substantial like chemotherapy to treat cancer, your soul can also suffer from spiritual illnesses such as ghadab (anger), riya (showing off), takabbur (pride and arrogance), hasad (envy), lack of shukr (ingratitude), hubb al-jah (love of fame), hubb al-mal (love of wealth), and the like.
Spiritual health is fundamentally different however, and in some respects more important. Why is this? The detrimental consequences of a physical illness will come to an end upon death; whereas, the evil result of a spiritual illness will begin upon death, and will last for eternity.