Introduction 1 1 2 3 4 5 6 In this short review we outline the morphology and biochemistry of normal discs and the changes that arise during degeneration. We review recent advances in our understanding of the aetiology of this disorder and discuss new approaches to treatment. Disc morphology The normal disc 1 7 8 9 10 3  11 12 10 13 14 13 13 8 15 16 17 Degenerated discs 18 2 15 19 20 21 22 21 et al 5 Biochemistry Normal discs 23 24 25 26 27 28 29 31 32 24 Changes in disc biochemistry with degeneration 33 24 34 35 36 37 38 in vitro  39 29 30 40 Effect of degenerative changes on disc function and pathology 33 41 33 42 43 44 1 45 46 47 48 49 50 Disc herniation 1 in vitro  51 52 4 53 54 2 2 55 56 57 58 59 30 Aetiology of disc degeneration 60 61 62 63 64 Nutritional pathways to disc degeneration 65 In vitro 66 67 68 69 16 70 71 72 73 74 75 65 76 77 78 79 80 81 in vivo  82 in vitro  65 Mechanical load and injury 83 84 85 86 63 87 88 89 91 91 5 92 93 94 95 96 Genetic factors in disc degeneration 97 99 100 101 3 102 103 COL9A2  COL9A3 104 105 COL9A2  103 106 107 108 109 110 111 114 111 112 114 115 116 112 117 97 114 118 New therapies 119 93 120 121 122 Because disc degeneration is thought to lead to degeneration of adjacent tissues and be a risk factor in the development of spinal stenosis in the long term, new treatments are in development that are aimed at restoring disc height and biomechanical function. Some of the proposed biological therapies are outlined below. Cell based therapies 123 124 125 126 127 21 128 129 130 131 65 132 At present, although experimental work demonstrates the potential of these cell-based therapies, several barriers prevent the use of these treatments clinically. Moreover, these treatments are unlikely to be appropriate for all patients; some method of selecting appropriate patients will be required if success with these therapies is to be realized. Conclusion 1 133 1 Competing interests None declared. Abbreviations MMP = matrix metalloproteinase.