There are some hindrances to healing that God expects us to correct.
Unconfessed sin in our lives is one hindrance. We are never perfect in this life, but I am referring to any specific sin that we have refused to release. This may especially include unforgiveness or bitterness towards others. It has been shown that such attitudes can affect our physical health.
Trusting in man and not God. The Bible says, "It is better to trust in the LORD than to put confidence in man" (Psalm 118:8, KJV). A well-known evangelist who routinely sees many healings and miracles in Africa was preaching in Europe. He told his hearers that they will not see the miracles there that he sees in Africa, because they trust in their government health care system. He said the people in Africa see the healings and miracles because God is all they have. They cannot trust in man. So whether or not you are able to have medical help, make sure all your trust is in the Lord as if He is all you have.
Not recognizing (discerning) the Lord's body. This is rarely mentioned by others, but it is clearly Scriptural. Concerning partaking of the body and blood of our Lord at communion, Paul wrote, "A man ought to examine himself before he eats of the bread and drinks of the cup. For anyone who eats and drinks without recognizing the body of the Lord eats and drinks judgment on himself. That is why many among you are weak and sick, and a number of you have fallen asleep" (1 Corinthians 11:29-30). I believe he is speaking of not recognizing the body of Christ as they symbolically eat His body and drink His blood. Many believers angrily deny that others outside their particular church or group who also trust Christ are really His, thus not recognizing His body. This is not healthy!
Other reasons for sickness are: (1) Some people abuse their bodies, using harmful substances, or not allowing enough rest; (2) excessive stress; and (3) some people do not provide the body with nutritious food, often substituting junk or processed food. Much modern commercial food is deficient in nutrients and contains chemical additives, such as hormones and antibiotics, such as in meat and dairy products, and environmental pollutants. Also, many people violate God's food guidelines in the Bible and still expect to remain healthy. Examples are in Leviticus chapter 11, no longer a legal requirement but still the wisdom of God. Paul said, "Everything is permissible—but not everything is beneficial" (1 Corinthians 10:23). God's law of sowing and reaping always applies, but His grace transcends our past mistakes. Allow God to show you any area that needs attention.
Suggested prayer: Dear Heavenly Father, I see in your Word that healing is your will, and that the Lord Jesus has paid for my healing by His stripes. I believe what He has done. I confess and repent of (name any known sin, including sins of attitude). I confess and repent of (any unhealthy habits or carelessness in taking care of God's temple, your body). I receive my healing now, by faith. I thank you in advance. Be glorified in me and in my body. In Jesus' name. Amen." (Thank and praise Him until your healing is manifested, no matter how long it takes, and keep thanking and praising Him afterward.)