Unexplainable scratches on my body? they pop up partially healed! what can this be

Skin scratches: 2 possibilities. You may have "dermatographic urticaria" which is hypersensitive skin that develops a welt after physical contact. You can confirm this by scratching your skin and seeing whether the skin becomes raised. Other possibility is atopic dermatitis and scratching in your sleep. Cut your fingernails short and wear gloves to bed to see if it stops. Your doctor can prescribe medications.