Let me lay out clearly for you how I understand prayer for
physical healing. As I travel and meet people and listen to their concerns, and as I look at my own faith journey, I have come to believe that one of the most confusing and disturbing aspects of prayer is prayer for physical healing. Most of us have had at least one experience of praying for the healing of a terminally ill person, believing God would heal, claiming scriptural promises, sensing a God-given peace that surpasses understanding... only to see the person for whom we prayed succumb to the illness and die. This experience has left in its wake many broken and disillusioned prayers. We feel that our prayers made no difference, that the person died in spite of our best prayer efforts. 

Does God heal in response to prayer? 

Yes! Does God always heal in response to prayer? Yes! However, God will be the One to decide what form healing will take and by what method He will bring healing in response to prayer.
   
We cannot treat God's holy, precious Word as if it were a catalog from which we can place an order at the divine warehouse. He has a perfect, good, pleasing, and tailor-made design for each situation on earth. God's way is to prepare the answer before the need appears. Before you
knew about the illness, God knew about it. God has already planned and purposed an outcome that will " prosper you and not harm you," an outcome that will give you "a future and a hope" (Jer. 29:11). Prayer releases onto the earth the perfect design of God for that specific
situation. 

God heals in many ways. When you pray for a person who is sick- either something as simple as a headache or as life-threatening as cancer- God heals. Your prayers access His power and He always intervenes directly
because of your prayers. Never feel that the situation took the same course it would have taken without your prayers.
    
What are some ways that God heals in response to prayer?

God can heal directly, suddenly, outside His created order.  God encourages us never to limit Him, but to know that nothing is impossible for Him. Sometimes He does so at the moment of prayer. Other times He does so after much concentrated prayer. Other times He does so weeks, months, even years after prayer for healing has begun.

God, in response to prayer, can bring healing by using the natural healing processes of the body.

The natural healing processes of the body as God created them are amazing, too wonderful to fully comprehend. God created the world and everything in it with deliberate purpose. Every detail is planned by Him for His loving intentions. Colossians 1:16-17, speaking of God the Son, says: "For by him all things were created... all things were created by him and for him. He is before all things, and in him all things hold together."      Everything was created by Him. Therefore, nothing in creation is a mystery to Him. No disease, no germ, no bacteria, no infection stumps God.

God may heal by means of scientific advances and medical technology. 

Is this not a miracle, directly from God? Human beings have no knowledge except that which God has given. God has hidden all the treasures of wisdom and knowledge in His Son. (Col. 2:3) Whether to keep a matter hidden, or allow a matter to be discovered, is God's choice. "It is the glory of God to conceal a matter; to search out a matter is the glory of kings" (Prov. 25:2). Man did not create science. Rather, man discovers the principles of God's creation. Knowledge is never new, only newly discovered. "Is there anything of which one can say, 'Look! This is something new'? It was here already, long ago; it was here before our time" (Ecc.1:10). When God uses medical technology or medical advances
to heal, thank Him for His miracle. God knows how to empower doctors and nurses, how to enhance the potential of medicine. He is in control.

God, in response to prayer, may leave a chronic physical ailment in place in order to heal at a deeper level. 

Nothing comes into your life without God's direct permission. God only allows difficulties into our lives because He can use them for higher good. He can do more through them than He could do without them. Even though Paul's "thorn in the flesh" came to him as a messenger from Satan to defeat and discourage Him, God allowed it and chose to leave it in Paul's life for His bigger purpose.

God may choose, in response to your prayers, to allow the disease to take its natural course and end in death. 

Death is not defeat. Because of Jesus, death has no sting and the grave has no victory. Death only removes our loved ones from our sight. Death is the doorway into
eternity, for which we were created. In Hebrews 9:27 we read: "...man is destined to die once." Eternity brings us fully into our joyous destiny, and our complete and eternal healing. Illness of any kind will never again touch the person healed in eternity.
     
As God heals, He is working according to an eternal strategy. He is not limited to earth-bound, time-bound goals. What is seen will pass away, but what is unseen is eternal. God always heals in response to prayer. Don't be afraid to pray boldly and unabashedly for healing. God will heal!  I can certainly not describe all of God's ways of healing, because I do not know them all. Pray and watch for Him to work. Rejoice in His ways, Who is great in counsel and mighty in deed.