From Deuteronomy, chapter 28, we get a clear picture as to what constitutes a curse and what constitutes a blessing. This is the summation of the curses: humiliation, mental and physical sickness, family breakdown, poverty, defeat, oppression, failure, God's disfavour.
If you ponder on that list, even more so if you read the 28th chapter of Deuteronomy on which it's based, you'll find that one major element in the curses is mental and physical sickness. I'll develop this a little further by reading some passages from Deuteronomy 28 where the curses are specified and many times in great detail. Beginning in Deuteronomy 28, verses 21 and 22:
"The Lord will plague you with diseases until he has destroyed you from the land you are entering to possess. The Lord will strike you with wasting disease, with fever and inflammation, scorching heat and drought, with blight and mildew, which will plague you until you perish." (NIV)
Notice that it specifies there diseases in general, and then particularly, wasting disease, fever and inflammation.
And then, in verse 61 it goes on to say if there should be any diseases not included in the entire list:
"The Lord will also bring on you every kind of sickness and disaster not recorded in this Book of the Law." (NIV)
In other words, every kind of sickness, disease is part of the curse. Logically, therefore, if Jesus bore the curse for us, then he bore our sicknesses, both mental and physical, and sure enough, that's exactly what the Bible declares.
We look first of all in Isaiah 53, verses 4 and 5. Again, this is the prophetic preview of the sufferings of Jesus on the cross:
"Surely he [that's Jesus] took our infirmities and carried our sorrows [but the more literal translation is pains]. Surely he took up our infirmities and carried our pains, yet we considered him stricken by God, smitten by him, and afflicted. But he was pierced for our transgressions, he was crushed for our iniquities; the punishment that brought us peace was upon him, and by his wounds we are healed." (NIV)
Thank You, Jesus, that You also took my infirmities, sorrows and pains. Thank You, Jesus, that even sickness has been overcome by You on the Cross. Help me, Lord Jesus, through Your Holy Spirit, to fully enter into also this part of the blessing that You have obtained for me on the Cross. In Jesus’ Name, Amen!
For a complete study on the subject of Healing, we recommend the book 'God’s Word Heals’.